The Heterogeneity in the Relationships Between Psychological Drivers and Construction and Demolition Waste Management Intention and Behaviors Among Tunnel Construction Managers: Insights from Personality Profiles

Abstract

Effective tunnel construction and demolition (C&D) waste management is a critical issue in the context of sustainable development, and C&D waste management measures guided by 3R principles (Reduce, Reuse, and Recycle) comply with the circular economy. In this study, an extended theory of planned behavior model based on the existing literature was proposed to identify the drivers of tunnel construction managers’ intention to implement effective waste management measures; then, the respondents were classified into four groups according to personality traits to explore the effects of personality profile on the heterogeneity in relationships between psychological drivers and C&D waste management intention and behaviors. The results show that all TPB constructs, policies, and environmental concern are significant predictors of managers’ intention to manage C&D waste properly. Then, considerable variance in the driving effects of various psychological drivers across different groups is witnessed. For the positive and temperate participants, subjective norms and policies are the most effective driving factors. However, PBC and environmental concern show a stronger relationship with the conservative and introverted participants’ intentions to adopt effective waste management measures. The findings are beneficial to developing corresponding management measures to promote effective C&D waste management.

1. Introduction

With the rapid urbanization process and economic development in China, a considerable amount of construction and demolition (C&D) waste has been generated, including waste from the completion of a series of infrastructure constructions [1,2]. According to statistics, the quantity of C&D waste is still increasing and accounts for about 30–40% of the total municipal solid waste in China [3]. In China, the common practice to deal with C&D waste is to dispose of it in landfill or dump it directly without proper treatment, which undoubtedly poses a threat to sustainable development. Generally, most scholars focus on the treatment of general C&D waste, so some special industries like tunnel construction lack attention. As for the tunnels, which are usually far from urban areas, the C&D waste leads to more serious adverse effects on the environment, such as soil contamination induced by hazardous materials, land occupation, hazardous gas emissions, leachate contamination of groundwater, and biodiversity loss in surrounding areas, due to a lack of public attention [4,5].

The disposal of C&D waste without proper treatment leads to various environmental issues. Therefore, effective C&D waste management measures are essential to achieving the goal of sustainable development worldwide. The application of the 3R principles (Reduce, Reuse, and Recycle), which is beneficial in terms of environmental protection, resource conservation, and the economy, offers a comprehensive framework for sustainable C&D waste management; promoting waste management measures guided by the 3R principles is a promising strategy for the sustainable construction industry. As the final decision makers and implementers of C&D waste management, construction managers’ intentions and behaviors regarding effective C&D waste management play an important role in transforming the current waste disposal methods into more environmentally friendly ones. A series of scholars have made efforts to identify the powerful drivers urging construction managers to adopt effective C&D waste management measures to protect the environment and save natural resources [1,6,7,8,9]. Li et al. proposed an extended theory of planned behavior (TPB) model by incorporating additional constructs (knowledge and personal norms) to explore the construction waste reduction behavior of contractor employees [10]; the results showed that all factors exerted a significant impact. Several scholars presented a conceptual framework that considered TPB theory, institutional pressures, and environmental consciousness to analyze the builders’ intention to recycle C&D waste [11]. A previous study analyzed the implementation effects of three C&D waste disposal policies on the acceptance and willingness to adopt reduction, reuse, and recycling methods [12]. The results found that guidance, incentives, and mandatory policies all effectively promote C&D waste management. Most of the current studies focus on general C&D waste, while few pay attention to the waste of one specific industry like tunnels, which are usually far from the urban areas and lack regulation and public attention. Meanwhile, although many researchers have explored the factors that promote sustainable C&D waste management, most have focused on a single measure, such as waste reduction or recycling. Few studies have focused on developing a research framework for predicting comprehensive waste management measures, and there is a particular lack of attention to tunnel C&D waste. If C&D waste management measures guided by the 3R principles are implemented, the waste could be converted into useful resources, a process that is economically beneficial. Meanwhile, the environmental problems caused by the improper treatment of harmful waste could be avoided. Consequently, it is necessary to investigate the psychological determinants that can promote the adoption of comprehensive tunnel C&D waste management measures.

Meanwhile, some previous studies witnessed individual heterogeneity in terms of the relationship between psychological drivers and pro-environmental intentions and behaviors, and the heterogeneities are partly attributed to individual differences in demographic factors (like gender and personality traits), cultural background, and personal values. Personality traits reflect long-term stable patterns in cognition, thinking, and feeling [13], and individuals with various personality traits may show differences in the perception of psychological variables driving them to carry out pro-environmental behaviors, which has been validated [14,15]. Therefore, it could be speculated that construction managers with different personality traits perceive psychological drivers differently and have various mechanisms underlying their behaviors regarding waste management. Thus, it is necessary to explore the effects of personality traits on the relationships between variables and effective waste management behaviors to develop tailored strategies for the targeted group.

This study attempts to identify the psychological drivers of tunnel construction managers’ intention to manage C&D waste properly and explore the heterogeneity in relationships between psychological drivers and effective C&D waste management intention and behaviors due to the different personality traits among the managers. As shown in Figure 1, the research process of this paper can be divided into four steps:

(1) first, a literature review was conducted to preliminarily identify the factors driving the managers to adopt effective C&D waste management measures; since few studies have focused on tunnel C&D waste management, this study referred to previous studies considering other types of projects;

(2) second, the structural equation model was used to test the hypotheses of the proposed model and revealed the relationship between the psychological drivers and managers’ intentions and behaviors;

(3) in the third step, the respondents were classified into four clusters (positives, temperates, conservatives, and introverts) according to their personality traits on the basis of the Big Five Personality Traits;

(4) finally, the heterogeneity in relationships between psychological drivers and effective C&D waste management intention and behaviors was investigated by considering the path coefficients and p-values.

2. Literature Review and Research Framework

2.1. Extended Theory of Planned Behavior and Intention to Implement Construction and Demolition Waste Management Strategies

The theory of planned behavior (TPB) is one of the popular psychological theories explaining individuals’ intentions and behaviors in terms of waste management [16]. This theory argues that the plan and form of an intention are correlated with conducting the related behavior and that intentions are influenced by three variables (attitude, perceived behavioral control, and subjective norms) [17]. Attitudes represent how an individual evaluates a particular behavior. Perceived behavioral control (PBC) reflects how easy or difficult an individual perceives the behavior is to perform. Subjective norms are perceived social pressures from relevant other people regarding a particular behavior. Many scholars validated the powerful capacity of TPB in predicting contractors’ effective C&D waste management behavior [1,18]. For example, Yuan et al. highlighted the important role of attitude in motivating managers to adopt effective C&D waste management [19]. Effectively dealing with C&D waste, as opposed to simply dumping or landfilling it, requires increased labor, additional space, and extended time for waste pretreatment like sorting, as well as optimal construction procedure design and the implementation of new recycling technologies [20,21,22,23]. Consequently, fewer perceived difficulties could boost the managers’ intention to manage the waste properly. Moreover, construction managers have to collaborate with other participants like design and development companies regarding important affairs during the construction process, such as waste management. Meanwhile, construction activities are supervised by the government and public, and improper behavior that leads to adverse effects on the lives of residents would be punished and prohibited by the administrative department. Therefore, it can be inferred that subjective norms regulate managers’ waste management behaviors and facilitate effective measures guided by the 3R principles.

Based on the statements above, hypotheses are proposed as follows:

H1: 

Attitude is positively linked to the intention to manage C&D waste properly.

H2: 

PBC is positively linked to the intention to manage C&D waste properly.

H3: 

Subjective norms are positively linked to the intention to manage C&D waste properly.

Apart from the constructs from TPB theory, a common approach is to add other factors to enhance the predictive power regarding individuals’ intentions in the proposed model. Scholars have emphasized the importance of individuals’ moral obligations in predicting altruistic behaviors [24]. Unlike subjective norms reflecting the satisfaction of normative expectations, moral norms are adhered to without condition, driven by emotional responses [25,26]. Previous studies proved it more likely that individuals with strong personal norms are more likely to perform altruistic behavior [27,28]. For example, Ding et al. validated the positive relationship between personal norms and the intention to recycle C&D waste [1], thus it is reasonable to assume that tunnel construction managers with higher levels of moral norms prefer to adopt effective waste management measures. Evidence showed that cost might be the primary driver for local contractors to deal with the C&D waste in the absence of a regulatory framework [29]. Consequently, policies issued by the government that use economic incentives and penalties to regulate construction and demolition (C&D) waste management are beneficial in promoting effective waste management measures [30]. Meanwhile, Huang et al. pointed out that the lack of design standards and guidance for waste collection and sorting and the immature market for recycled waste products also inhibited managers from reducing, reusing, and recycling the waste [3], and the government can smash these obstacles by developing and implementing related policies. Environmental concerns reflect how individuals are aware of the decline and degradation in environmental quality and are considered a source of concern and another important factor that predicts individuals’ pro-environmental behavior [31]. A previous study proved the positive relationship between environmental consciousness and C&D waste recycling [11]. It can be deduced that managers with higher levels of environmental consciousness are more inclined to adopt effective C&D waste management measures. Therefore, we propose the following hypotheses:

H4: 

Moral norms are positively linked to the intention to manage C&D waste properly.

H5: 

Policies are positively linked to the intention to manage C&D waste properly.

H6: 

Environmental concern is positively linked to the intention to manage C&D waste properly.

2.2. Construction and Demolition Waste Management and 3R Principles (Reduce, Reuse, and Recycle)

C&D waste occupies a considerable portion of the total amount of waste worldwide and is usually randomly dumped or disposed of in landfills to reduce construction costs. This waste disposal method leads to considerable environmental burdens and threats, like soil contamination, water pollution, air quality degradation, and health risks. The detrimental effects on the environment could be amplified for the tunnels, which are generally far from the urban areas and located in the mountain areas, due to a lack of public attention.

Compared with the traditional landfill methods, C&D waste management practices guided by the 3R principles (reduce, reuse, and recycle) are beneficial in terms of environmental and economic aspects and are closely linked to the concept of the circular economy. The details regarding the 3R principles are presented in

Table 1. Details about the 3R principles.

Item	Specific Measures	Typical Features
Reduce	(1) Appropriate and precise plans should be formulated before the commencement of the project to avoid excess material ordering and waste (2) Efficient and resource-efficient construction methods should be adopted to minimize waste (3) Some new technologies like the BIM (Building Information Model), precast construction, and others could assist the design or construction process	(1) Reducing the waste has the lowest adverse impact on the environment (2) It should be granted the priority when developing CDW management plans
Reuse	(1) Properly separating or sorting the waste at the source could improve efficiency (2) The reused construction materials should meet regulatory requirements (3) The abandoned construction projects could be modified to serve as other projects like a creative industrial park	(1) The cost of reusing the waste is relatively low
Recycle	(1) Separating recyclable materials (concrete, metals, wood, etc.) from non-recyclable waste should be carried out (2) The waste relies on new technology to be broken down to make new materials and objects	(1) The price and applicability of recycled waste products depend on the technology and type of materials

. Reducing waste is considered the optimal management measure and has the lowest environmental impact. The best way to reduce waste is to minimize waste generation in the initial stage; thus, a comprehensive, conscious, and innovative design that plans and optimizes construction processes is required to avoid the excessive generation of C&D waste from the source [32]. When formulating precise plans, new information technologies like the BIM (Building Information Model) could assist the design from the perspective of improvement of waste management. Meanwhile, other new technologies like precast construction also reduce waste generation on-site, and previous studies have validated that conventional construction produces two times more waste and consumes three times more materials than precast construction [33,34]. Reusing waste refers to the practice of using applicable materials again for either the original purpose (conventional reuse) or a different function (creative reuse or repurposing) instead of discarding them. This measure usually requires construction personnel to deconstruct buildings to salvage valuable materials like doors, windows, bricks, and steel bars, and this process needs additional workers to properly sort or separate the waste on-site and is dependent on the properties and volume of the materials [35]. For example, crushed concrete can be used as the sub-base and base in road construction or foundations. Recycling waste represents the production of new materials or objects by breaking down C&D waste and is considered one of the commitments to the environment that is most visible to the public. This measure has high requirements for recycling technology like concrete and cement separation, concrete and aggregate recycling, and even the carbonization of C&D waste [3]. The cost and applicability of recycled materials depend on the technology and type of materials [3,35]. Scholars have found that more than half of C&D waste could be reused or recycled, which validated the great potential of the implementation of the 3R principles [35,36]. The 3R principles could apply to C&D waste at tunnel construction sites at different stages. As mentioned above, measures to reduce waste can be implemented during the design stage, while reusing and recycling waste is feasible throughout the entire construction or deconstruction stage. It should be noted that measures guided by the 3R principles should be tunnel-specific and correspond with the characteristics of the tunnel industry. For example, accurate design for the arrangement of explosives or new technology, like precast concrete, could be adopted to reduce the earthwork excavation volume. Consequently, it is reasonable that tunnel construction managers who intend to manage C&D waste properly deal with the waste under the guidance of the 3R principles. Therefore, we propose the following hypotheses:

H7: 

Intention to manage the C&D waste properly is positively related to the behavior of reducing C&D waste.

H8: 

Intention to manage the C&D waste properly is positively related to the behavior of reusing C&D waste.

H9: 

Intention to manage the C&D waste properly is positively related to the behavior of recycling C&D waste.

As stated above, Figure 2 presents the framework and hypotheses of this study.

2.3. Personality Profile and Pro-Environmental Behaviors

Personality traits reflect long-term stable psychological characteristics that manifest as enduring tendencies in cognition, feelings, and decision making [13]. The Big Five Personality Model is a widely accepted model and serves as a fundamental theory of personality traits in contemporary psychology [37]. There are five main dimensions of personality traits in the model: extraversion, agreeableness, conscientiousness, neuroticism, and openness [38]. Extraversion features high levels of energy, sociability, and assertiveness. Agreeableness reflects greater tolerance toward other people and heightened empathy. Conscientiousness represents a strong sense of responsibility, high self-discipline levels, and a desire for achievement. Neuroticism refers to the tendency to experience negative emotions. Openness entails a preference for innovative thinking and reflects a person’s degree of curiosity and ability for abstract thinking.

Studies have utilized personality traits to explain differences in pro-environmental behavior [39,40], and there are generally two methods for considering these traits. Firstly, personality traits are considered separate constructs that predict pro-environmental intentions and behaviors either on their own or in conjunction with other constructs. For example, Wang et al. revealed that individuals with openness and extraversion traits were proactive in engaging in pro-environmental behaviors, while neuroticism traits were negatively related to pro-environmental behaviors [41]. Tang et al. validated the positive role of extraversion and agreeableness in predicting the respondents’ attitudes toward green hotels [42]. Roos et al. investigated the relationship between personality traits and public-transport-taking behaviors among Swedish residents and found that openness and agreeableness contributed to pro-environmental behaviors [43]. The research highlighted the significant roles of personality traits in predicting pro-environmental behaviors. However, several scholars divided the respondents into a few groups based on the five personality traits and explored the heterogeneity in relationships between the psychological drivers and pro-environmental intentions and behaviors among different groups, which is called the people-centered approach [44]. Liu et al. divided the respondents into four groups (the positives, the temperates, the conservatives, and the introverts) and observed significant heterogeneity in energy-saving behavior among the four groups [45]. Wang et al. also explored how the personality profile composition influenced people’s behavioral/decision-making patterns [46]. It should be noted that few studies have linked the relationship between the personality profile and tunnel construction managers’ intention to deal with C&D waste effectively, and this could create barriers to formulating plans to promote C&D waste management measures guided by the 3R principles.

This study preferred the second approach because the first method overwhelmingly focuses on the separate correlation between each trait and behavior, while insufficient attention has been paid to the complex interactions between different dimensions of personality traits. Consequently, this study clustered the tunnel construction managers into four categories based on their personality profiles and explored the heterogeneity in the predictive capacity of psychological drivers that promote managers to adopt effective C&D waste management measures among different groups of different personality types.

3. Methods

3.1. Sample and Data Collection

Properly selecting the target group is crucial, as it can guide policymakers in developing effective measures and enhance the practicality of research findings. As the final decision makers and implementers of C&D waste management, the tunnel construction managers are the target group in this study. Internet-based surveys are a convenient and reliable method to collect self-reported data and have been widely employed in numerous studies [47]. Consequently, the participants in this study were recruited from various tunnel construction sites across China through the Questionnaire Star, which is an online questionnaire distribution platform. The survey took place in January 2023. Due to the particularity of the industry, most of the tunnel construction workers and managers are male. Although there are a few female managers in the tunnel construction industry, to improve the applicability of research results, only male participants were considered. However, this choice could lead to potential gender bias, which will be discussed in Section 5.2. Because the whole sample will be divided into several groups based on their personality traits, a sufficient sample is needed to ensure the reliability of the research results, and 4659 questionnaires were collected. All the participants signed the consent form, and anonymity for respondents was guaranteed with the assurance that the results would be used only for scientific research to collect unbiased results and ensure the validity and reliability of the results. Rigorous screening was carried out to remove the invalid participants. Firstly, the question, are you a manager at the tunnel construction site, was adopted to screen out the unqualified participants. Secondly, invalid responses (unreasonable consecutive replies and wrong answers in the trap questions) were also eliminated. Finally, 4121 valid questionnaires were retained and used for further research. The research protocol in this study was approved by the Ethics Committees of Sichuan Normal University.

Table 2. Descriptive statistics of demographic characteristics (N = 4121).

Category	Demographic Characteristics	Number	Frequency (%)
Age (years)
	<30	47	1.14
	30–39	1876	45.52
	40–49	1520	36.88
	50–60	632	15.34
	>60	46	1.12
Level of education
	College diploma or below	1359	32.98
	Bachelor’s degree	2484	60.28
	Master’s degree or above	278	6.74
C&D waste management-related work experience (years)
	<10	817	19.83
	10–20	1318	31.98
	>20	1986	48.19

shows the demographic characteristics of the valid participants. The median age of the construction managers is between 41 and 50, and respondents aged from 30 to 39 and from 40 to 49 account for 45.52% and 36.88% of the sample, respectively. The majority of the respondents (60.28%) hold a bachelor’s degree, while 6.74% of the interviewed managers hold a higher degree. It should be noted that over 80% of the respondents had more than 10 years of C&D waste management-related work experience, which ensures the reliability of the survey results.

3.2. Measurements

The questionnaire consisted of four parts: (1) respondents’ socio-demographic information; (2) psychological drivers that may urge managers to adopt effective C&D waste management measures; (3) measuring items to determine the respondents’ personality traits; and (4) managers’ intentions and behaviors regarding waste management measures. The measurement items for psychological drivers and respondents’ intentions and behaviors were derived from established and validated scales used in previous research [1,18,48] except for policies and were modified according to the research context of this study. In terms of policies, three items originate from several related studies [12,18] and are adopted. The Mini-IPIP, which contains 20 items [49], was adopted to collect the respondents’ personality characteristics in the third part. Studies have proved the validity and applicability of Mini-IPIP in the field of pro-environmental behaviors [45,50]. In this study, all constructs in parts 2, 3, and 4 are measured using a 7-point Likert scale. Moreover, a test question, are you a manager at the tunnel construction site, and three trap questions are added to the questionnaire to ensure the qualification of the respondents and the reliability of the collected data.

Before the formal survey phase, a preliminary survey phase where the questionnaire was distributed to 22 experts in the tunnel construction industry and academia to detect grammar and expression issues was conducted. According to the experts’ feedback and suggestions, appropriate modifications were made to ensure that respondents understood the measuring items clearly and comprehensively.

3.3. Data Analysis

Apart from the literature review, this study adopted a three-step approach for data analysis, as shown in Figure 1.

When determining the effects of the psychological drivers of the C&D waste management intention and behaviors for the whole sample, Partial Least Squares Structural Equation Modeling (PLS-SEM) was employed to explore the psychological patterns of the overall model. SEM has the advantages of factor analysis, multiple regression analysis, path analysis, and other approaches to test causality between the observed variables and latent variables [51] and has been widely adopted for psychological and behavioral research. Meanwhile, PLS-SEM does not require a strict normal distribution in the collected data, performs well with smaller datasets, and is suitable for complex models featuring a large number of constructs and relationships, which expands its scope of application. Moreover, PLS-SEM comprises a comprehensive evaluation of both the measurement model and structural model. Indexes regarding indicator reliability, internal consistency, and convergent validity should be considered when the measurement model is evaluated, and the values of the path coefficients and R-squared are adopted for the assessment of the structural model. The two-step evaluation ensures that the results for the proposed model are both reliable and valid. When clustering the respondents into different clusters based on personality characteristics, the k-means algorithm was employed, and the number of clusters was set to four to balance the compactness and distinctiveness [52]. Meanwhile, a one-way analysis of variance (ANOVA) was also conducted to compare the psychological drivers and intentional and behavioral characteristics of different clusters. ANOVA is one of the most popular statistical methods in the field of social sciences and is usually used to detect significant differences in the mean of the variables and determine the variables that will influence the experiment results. In the final step, SEM was conducted to investigate the psychological and behavioral patterns of each cluster. This study also compares the characteristics of each cluster with the overall model to identify the heterogeneity in the relationships between psychological drivers and effective waste management intention and behaviors among different clusters.

SmartPLS 3.3.9 was used for SEM analysis, and the ANOVA and clustering analysis were conducted with the help of SPSS 24 in this study.

4. Results

4.1. Overall Analysis

This section analyzed the C&D waste management intention and behaviors, along with their psychological drivers for the whole sample. The SEM analysis comprises assessment of measurement and structural models to ensure the validity and reliability of the self-reported data, and the details are as follows.

4.1.1. Measurement Modeling

The convergent validity (CV) and discriminant validity (DV) of the measurement model are evaluated in this section. The correlation between different items under the same construct was assessed using CV, and four indexes were included: (1) Cronbach’s alpha, (2) Composite Reliability (CR), (3) Average Variance Extracted (AVE), and (4) factor loading. Cronbach’s alpha and composite reliability aim to test the internal consistency and reliability of the constructs, and the values of Cronbach’s alpha and CR are expected to be over 0.70 [53]. AVE reflects the explanatory capacity of constructs for their measured items, while factor loading represents the relationship between the items and the corresponding construct. The threshold values for AVE and factor loading should be greater than 0.50 and 0.70, respectively [53]. The DV evaluates whether measuring items from other constructs can be distinguished, and the Fornell–Larcker criterion and Heterotrait-Monotrait (HTMT) ratio are generally adopted for the DV examination. According to the Fornell–Larcker criterion [54], sufficient DV is ensured if the square root of one construct’s AVE is greater than the correlation coefficients between other constructs. In terms of the HTMT ratio, it is required that the HTMT ratio should be no more than 0.90 [55].

Table 3. The convergent validity test results for the whole sample.

Construct	Items	Standardized Outer Loading	Cronbach’s Alpha	Composite Reliability	Average Variance Extracted (AVE)
Attitude
	ATT1	0.745	0.841	0.867	0.567
	ATT2	0.819
	ATT3	0.716
	ATT4	0.687
	ATT5	0.790
PBC
	PBC1	0.833	0.857	0.888	0.614
	PBC2	0.719
	PBC3	0.865
	PBC4	0.745
	PBC5	0.744
Subjective norms
	SN1	0.866	0.871	0.892	0.673
	SN2	0.809
	SN3	0.778
	SN4	0.826
Moral norms
	MN1	0.746	0.798	0.825	0.612
	MN2	0.816
	MN3	0.783
Policies
	PO1	0.709	0.803	0.811	0.591
	PO2	0.856
	PO3	0.733
Environmental Concern
	EC1	0.792	0.818	0.836	0.632
	EC2	0.875
	EC3	0.709
Intention
	INT1	0.783	0.844	0.862	0.675
	INT2	0.814
	INT3	0.866
Reduce
	RD1	0.709	0.705	0.713	0.554
	RD2	0.778
Reuse
	RU1	0.754	0.733	0.749	0.599
	RU2	0.793
Recycle
	RC1	0.855	0.826	0.835	0.717
	RC2	0.839

lists the results of the CV assessment, and all Cronbach’s alpha and CR values for constructs are greater than 0.70. The AVE values range from 0.554 to 0.717, and most of the factor loadings are greater than 0.70, with a few exceptions close to the threshold value. Consequently, sufficient convergent validity was obtained for the measurement model. From

Table 4. Fornell–Larcker criteria.

	ATT	PBC	SN	MN	PO	EC	INT	RD	RU	RC
ATT	0.753
PBC	0.407	0.784
SN	0.571	0.382	0.820
MN	0.671	0.517	0.431	0.782
PO	0.569	0.399	0.584	0.334	0.769
EC	0.610	0.468	0.539	0.406	0.569	0.795
INT	0.511	0.631	0.659	0.340	0.411	0.613	0.822
RD	0.651	0.527	0.557	0.634	0.376	0.443	0.517	0.744
RU	0.534	0.406	0.614	0.528	0.576	0.628	0.484	0.642	0.774
RC	0.711	0.563	0.526	0.525	0.423	0.406	0.371	0.511	0.576	0.847

and

Table 5. HTMT results.

	ATT	PBC	SN	MN	PO	EC	INT	RD	RU	RC
ATT
PBC	0.353
SN	0.798	0.344
MN	0.507	0.463	0.622
PO	0.427	0.525	0.433	0.519
EC	0.538	0.636	0.547	0.763	0.567
INT	0.875	0.726	0.697	0.421	0.804	0.376
RD	0.406	0.396	0.358	0.506	0.467	0.744	0.328
RU	0.839	0.579	0.471	0.549	0.626	0.657	0.532	0.733
RC	0.651	0.601	0.559	0.767	0.501	0.833	0.641	0.367	0.438

, the results of this study satisfy the requirements regarding the DV assessment. In summary, the measurement models have good reliability and validity and the study could proceed to the analysis of the structural models.

4.1.2. Structural Modeling

In this section, the study runs 5000 bootstraps of 4121 valid participants to test the hypotheses of the proposed model. Figure 3 illustrates the results of the hypotheses for the overall model, and it can be found that all the hypotheses are valid except for H4 (β = 0.089, p > 0.05), which indicates that the variable moral norms is not a psychological driver for the whole sample to dispose of C&D waste properly.

Table 6. The path coefficients in the overall structural model (* denotes p < 0.05, ** denotes p < 0.01, and *** denotes p < 0.001).

Hypothesis	Tested Relationship	Path Coefficient	Standard Deviation	T Statistics	p Values
H1	ATT→INT	0.243	0.056	4.339	0.000 ***
H2	PBC→INT	0.116	0.045	2.578	0.010 **
H3	SN→INT	0.176	0.051	3.451	0.001 ***
H4	MN→INT	0.089	0.061	1.459	0.144
H5	PO→INT	0.208	0.048	4.333	0.000 ***
H6	EC→INT	0.132	0.052	2.538	0.011 *
H7	INT→RD	0.354	0.078	4.538	0.000 ***
H8	INT→RU	0.432	0.089	4.854	0.000 ***
H9	INT→RC	0.263	0.082	3.207	0.001 ***

lists the details of the hypothesis results. It suggests that all TPB constructs (attitude, β = 0.243, p < 0.001, PBC, β = 0.116, p < 0.01, and subjective norms, β = 0.176, p < 0.001) and two additional constructs (policies, β = 0.208, p < 0.001 and environmental concern, β = 0.132, p < 0.05) significantly influence managers’ intention to manage the C&D waste properly. Regarding the underlying mechanisms that drive C&D waste management behaviors in accordance with the 3R principles, the intention exhibits the greatest influence on the behavior of recycling C&D waste (β = 0.432, p < 0.001), while the influence of intention on the other two C&D waste management behaviors is significant as well (reducing, β = 0.354, p < 0.001 and recycling, β = 0.263, p < 0.001). The R-squares for the intention and the behaviors of reducing, reusing, and recycling are 0.547, 0.125, 0.187, and 0.069, respectively, which reflects the strong explanatory power of the proposed model.

4.2. Personality Profile Development and Analysis

4.2.1. Cluster Results

To further explore the heterogeneity in relationships between psychological drivers and C&D waste management intention and behaviors, this study clusters the participants into different groups based on personality profiles delineated by the big five personality traits. The K-means clustering approach is used to classify the participants. The optimal number of clusters is important for the credibility of the data analysis, and the number is determined to be four based on considerations of compactness and distinctiveness by referring to previous studies [41,45]. Then, one-way ANOVA is adopted to test the difference in all the variables including personality traits, psychological drivers, intentions, and behaviors among the four groups.

Figure 4 lists the details of cluster results, and they are defined as follows: (1) positive (N = 861, 21%); (2) temperate (N = 1075, 26%); (3) conservative (N = 1230, 30%); (4) introverted (N = 955, 23%). It is evident that the four groups exhibit significant differences in personal traits. The positives have the highest score in most personality items but the lowest score on neuroticism (2.49). The temperates show balanced personality traits, while the score for neuroticism (4.78) is significantly higher than that for other groups. The conservatives have higher scores in terms of neuroticism (3.92), while the other traits are below the average. The introverted participants manifest lower scores in extraversion (3.71), agreeableness (3.89), and conscientiousness (4.50), while the levels of neuroticism (3.99) and openness (4.41) are above the average values of the whole sample.

The ANOVA results show significant differences in the psychological drivers and behavioral characteristics of four clusters, as shown in

Table A2. The ANOVA results and descriptive statistics of four respondent groups (* denotes p < 0.05, ** denotes p < 0.01, and *** denotes p < 0.001).

		ANOVA Results	Positive		Temperate		Conservative		Introverted
		p Value	Mean	Standard Deviation	Mean	Standard Deviation	Mean	Standard Deviation	Mean	Standard Deviation
Personality traits	E	0.000 ***	5.01	0.72	4.82	0.57	4.3	0.64	3.71	0.69
	A	0.000 ***	5.69	0.48	4.97	0.63	4.01	0.53	3.89	0.59
	C	0.000 ***	5.81	0.42	5.12	0.61	3.86	0.67	4.5	0.71
	N	0.000 ***	2.49	0.57	4.78	0.65	3.92	0.46	3.99	0.71
	O	0.000 ***	5.96	0.36	4.66	0.74	3.61	0.63	4.41	0.58
Psychological drivers	ATT	0.000 ***	5.89	0.79	5.63	0.55	4.91	0.65	4.35	0.72
	PBC	0.001 ***	5.38	0.65	5.22	0.49	4.56	0.67	4.33	0.56
	SN	0.007 **	5.44	0.59	5.29	0.61	4.89	0.63	4.64	0.71
	MN	0.000 ***	5.55	0.63	5.34	0.47	4.52	0.52	4.18	0.69
	PO	0.000 ***	6.11	0.34	5.87	0.41	5.21	0.53	4.98	0.55
	EC	0.028 *	5.23	0.66	5.87	0.44	5.45	0.56	5.41	0.53
Intention and behaviors	INT	0.019 *	5.43	0.57	5.13	0.61	4.98	0.48	4.77	0.56
	RD	0.000 ***	6.01	0.35	5.79	0.42	5.02	0.55	4.89	0.62
	RU	0.000 ***	5.23	0.59	5.11	0.61	4.57	0.51	4.12	0.56
	RC	0.000 ***	5.64	0.52	5.23	0.47	4.55	0.63	5.19	0.59

. In terms of psychological drivers, the positives had the highest score in most items except for the EC (5.23), while the temperates scored the highest in EC (5.87) and the second highest in other items. The conservatives and introverted participants scored lower in most items except for EC. Generally, the scores of the six psychological drivers gradually decrease from high to low from the positives to the introverted participants. As for the intention and three C&D waste management behaviors, the pattern is similar except that it is more likely for the introverted participants to recycle the C&D waste than the conservatives, and the positives’ self-evaluated scores in intention to manage the C&D waste properly and three behaviors are still the highest.

4.2.2. Structural Modeling Analysis by the Group

This section presents the heterogeneity in the relationships between psychological drivers and C&D waste management intention and behaviors among the four clusters.

Table 7. The structural modeling results for group analysis (* denotes p < 0.05, ** denotes p < 0.01, and *** denotes p < 0.001).

Cluster	Path	Original Sample	Standard Deviation	T Statistics	p Values
Positive
	ATT→INT	0.263	0.055	4.782	0.000 ***
	PBC→INT	0.058	0.042	1.381	0.168
	SN→INT	0.302	0.056	5.393	0.000 ***
	MN→INT	0.073	0.057	1.281	0.201
	PO→INT	0.311	0.052	5.981	0.000 ***
	EC→INT	0.109	0.046	2.370	0.018 *
	INT→RD	0.465	0.071	6.549	0.000 ***
	INT→RU	0.498	0.072	6.917	0.000 ***
	INT→RC	0.311	0.087	3.575	0.000 ***
Temperate
	ATT→INT	0.221	0.059	3.746	0.000 ***
	PBC→INT	0.103	0.056	1.839	0.066
	SN→INT	0.227	0.048	4.729	0.000 ***
	MN→INT	0.103	0.068	1.515	0.131
	PO→INT	0.284	0.051	5.569	0.000 ***
	EC→INT	0.096	0.053	1.811	0.070
	INT→RD	0.379	0.068	5.574	0.000 ***
	INT→RU	0.422	0.091	4.637	0.000 ***
	INT→RC	0.294	0.077	3.818	0.000 ***
Conservative
	ATT→INT	0.263	0.061	4.311	0.000 ***
	PBC→INT	0.135	0.067	2.015	0.045 *
	SN→INT	0.163	0.062	2.629	0.009 **
	MN→INT	0.097	0.054	1.796	0.072
	PO→INT	0.165	0.046	3.587	0.000 ***
	EC→INT	0.103	0.060	1.717	0.085
	INT→RD	0.313	0.083	3.771	0.000 ***
	INT→RU	0.413	0.081	5.099	0.000 ***
	INT→RC	0.174	0.075	2.320	0.020 *
Introverted
	ATT→INT	0.198	0.054	3.667	0.000 ***
	PBC→INT	0.164	0.043	3.814	0.000 ***
	SN→INT	0.139	0.038	3.658	0.000 ***
	MN→INT	0.082	0.062	1.323	0.187
	PO→INT	0.183	0.044	4.159	0.000 ***
	EC→INT	0.166	0.041	4.049	0.000 ***
	INT→RD	0.216	0.087	2.483	0.013 *
	INT→RU	0.365	0.102	3.578	0.000 ***
	INT→RC	0.232	0.096	2.417	0.016 *

shows the structural modeling results for group analysis.

The results show that four psychological factors can effectively explain the intention of the positive group to deal with the C&D waste properly, except for PBC (β = 0.058, p > 0.05) and moral norms (β = 0.073, p > 0.05). Among them, policies (β = 0.311, p < 0.001) are the dominant predictable variable, while subjective norm (β = 0.302, p < 0.001) also exhibits a significant role in predicting the intention. Meanwhile, the intention has a significant impact on the three behaviors for the positive group, while the significance ranking of the paths from intention to the three behaviors is consistent with that of the overall model. The three path coefficients for the positives are larger than those for the whole sample, which indicates that the intention to effectively deal with the C&D waste has a better explanatory capacity for the positive group.

As for the temperates, the four psychological factors show a significant correlation with the intention to engage in effective C&D waste management. Policies (β = 0.284, p < 0.001) have a higher impact, while the influence of the other three variables (attitude, β = 0.221, p < 0.001; subjective norm, β = 0.227, p < 0.001; environmental concern, β = 0.196, p < 0.001) is comparable and smaller than the policies. PBC (β = 0.103, p > 0.05) and moral norms (β = 0.103, p > 0.05) present an insignificant relationship with the intention. Similar to the positive group, the correlation between the intention and three C&D waste management behaviors for the temperates is significant and stronger than that of the overall model, except for reusing the waste (β = 0.422, p < 0.001).

The results for the conservatives reveal that all three TPB constructs and policies are statistically associated with the intention to deal with the C&D waste properly. It should be noted that attitude (β = 0.263, p < 0.001) presents the strongest influence, and the impacts of subjective norms (β = 0.163, p < 0.01) and policies (β = 0.165, p < 0.001) are comparable and greater than that of PBC (β = 0.135, p < 0.05). Moreover, the contributions of intention to the three behaviors are significant but lower than those of the overall model, which reflects the weakened capacity of intention to predict the C&D waste management behaviors for the conservative group.

The results for the introverted participants showed that all the factors present significant effects on the intention, except for moral norms (β = 0.082, p > 0.05). Attitude (β = 0.198, p < 0.001) and policies (β = 0.183, p < 0.001) are the top two important factors influencing the intention to deal with the waste properly, and moral norms is the only insignificant variable for all the groups. In addition, the influence of the intention on the three waste management behaviors for the introverted group is weaker than that of the whole sample, but all the path coefficients are still significant, which validates the powerful capacity of intention in predicting the corresponding behaviors.

5. Discussions

C&D waste management is critical to environmental protection, especially for tunnel construction sites that are remote from cities. Firstly, this study assessed the impact of six psychological variables on tunnel managers’ intention to deal with C&D waste properly, and the analysis showed that all TPB constructs, policies, and environmental concerns significantly promoted the intention, while moral norms did not emerge as a determinant. In line with previous studies [1,18], this study found that all TPB constructs were strong predictors of managers’ intentions to adopt effective C&D waste management measures. As a pillar industry of the country, the construction industry is subject to a series of regulations from the government due to its significant impact on residents’ lives in various aspects. Therefore, the policies issued by the government have a constraining effect on the behavior of construction enterprises, including C&D waste management, which has been validated by several studies [18]. For example, Lu et al. found that harsh punishments for illegal dumping significantly decreased the incidence of illegal waste disposal [56]. Moreover, scholars also emphasized the positive outcomes resulting from the implementation of the incentive policy [12,21,57]. People are likely to engage in pro-environmental behaviors when they are aware of environmental problems [24]. Previous studies validated the significant relationship between environmental concerns and waste management [58,59], which corresponds to the results of this study that managers who are concerned more about the environment prefer effective waste management measures. In this study, moral norms do not appear to be an important predictor of managers’ intention to adopt effective waste management measures, and previous research showed that the existence of subjective norms could weaken the capacity of moral norms to predict pro-environmental behavioral intention [45,50]. The importance of subjective norms and moral norms may vary across different pro-environmental behaviors due to their various characteristics. In this study, the construction process of tunnels is under the guidance and supervision of the design and development companies and the government, and thus their opinions play a crucial role in predicting managers’ intention to handle the waste. Moreover, many tunnel construction sites are far from urban areas or population-dense areas, which makes managers believe that improper treatment of waste is not supposed to cause adverse effects on other people. What is more, construction managers generally grant higher priority to the construction period and cost than environmental protection. Therefore, these factors lead to the insignificant impact of moral norms on the intention. Meanwhile, the results also indicated that the intention presented significant effects on the three effective waste management behaviors for the whole sample.

Furthermore, this research empirically evidenced the effects of personality characteristics on intrinsic mechanisms driving effective waste management intention and behaviors. Instead of searching for “green personalities” that promote pro-environmental behaviors [40], this study divided the whole sample into four groups based on their personality traits. The clustering and structural model results revealed significant variance in psychological attributes and the driving effects of various psychological drivers across different groups. Firstly, the positives and temperates performed better than the conservative and introverted participants in most psychological factors, as well as their intentions and behaviors regarding C&D waste management. Previous research showed that people who have higher sociability, more empathy, and a strong sense of responsibility are more likely to have better performance in pro-environmental behaviors [60], and these personality traits also promoted people’s psychological attributes [41]. The reasons may be that pro-environmental behaviors are generally altruistic behaviors, in which sociability, empathy, and responsibility play important roles in promoting. These findings are in line with the results of this study, where the positives and temperates scored higher in the measuring items regarding extraversion, agreeableness, and conscientiousness. Secondly, this study also highlighted the effects of personality profiles on the relationships between psychological drivers and waste management intentions and behaviors. Moral norms were the only psychological variable that was proved to be an insignificant determinant of the intention to deal with waste properly for all groups, while the relationships between the other psychological drivers and waste management intention and behaviors varied among different groups. Attitude and policies showed stable and significant effects on the managers’ intention to deal with the waste properly regardless of the groups. It should be noted that a decrease in the path coefficient from policies to intention was witnessed for the conservative group compared with other groups like the positives. However, the positive relationship was still significant, while the reduction in the coefficient may result from other variables’ powerful predictive capacity, like PBC. Tan et al. also highlighted the high explanatory power of attitude on residents’ low-carbon behaviors across groups with different personality profiles [44]. Compared with regular construction projects, tunnels generally feature higher costs, greater construction difficulty, and longer construction periods, and some of them belong to major infrastructure projects and are closely related to national security. Consequently, a large proportion of tunnels in China are state-owned and completed by state-owned enterprises, and thus it is more likely for the C&D waste management on the tunnel construction sites to conform to the relevant policies. What is more, scholars also pointed out that the lack of related standards, underdeveloped markets, and immature related technology are the main barriers to the promotion of the C&D waste management measures guided by the 3R principles [3,35], which also highlighted the significant role of policies. These findings shed light on individual homogeneity in C&D waste management behaviors and provide valuable insights for developing interventions for managers across the board. In addition, some studies found that social pressure was not an important psychological driver and could only present small effects on pro-environmental behaviors [46,61], and the reason for this might be limited public environmental awareness. However, the situation is different in this study, and the subjective norms are most effective in promoting appropriate waste management for the positives, except for the policies, and also present significant effects on other groups. The process of handling C&D waste is overseen by a combination of design and development companies, which are responsible for developing and recommending waste reduction strategies, and government agencies, which regulate and enforce waste management standards. Consequently, construction managers need to comply with the opinions of the design and development companies and the government regarding waste management. The psychological drivers for the temperates are similar to those for the positives, except that the path coefficients were slightly lower. Compared with the other groups, the conservative and introverted managers tended to be more sensitive to PBC, which indicated that related experience and the required space, time, and support played an important role in promoting their effective C&D waste management; some previous studies have also validated this phenomenon [45,46]. Moreover, environmental concerns also had a strong correlation with the conservative and introverted participants’ intention to deal with the waste properly, and thus the conservative and introverted participants care more about the environment than other groups and try to avoid the problems induced by human activities like handling the waste. This may be related to their higher scores in neuroticism and conscientiousness. It is easy for them to worry about environmental damage induced by improper waste treatment, and they tend to remedy such issues out of a sense of responsibility. In terms of the relationship between intention and waste management behaviors, the effects of personality traits could also not be disregarded. Consistent with the findings on the intrinsic mechanisms that drive managers’ intentions to implement effective waste management measures, the intention exhibited higher effects on the three waste management behaviors for the positives and temperates. This is because the positives and temperates had higher scores in terms of extraversion, agreeableness, and conscientiousness, which promote the psychological attributes and performance related to pro-environmental behaviors. For the other two groups, the introverted participants exhibited a higher preference for recycling the C&D waste than the conservatives. Openness reflects a preference for innovative thinking, and thus it is more likely for individuals with higher levels of openness to embrace new ideas and change the world with creative methods. Previous studies have claimed that people with higher levels of openness tend to adopt new energy-saving technologies like energy recycling and solar energy recovery systems [60,62]. As for recycling C&D waste, a series of new relevant technologies are required to translate the waste into new products. Consequently, the fact that introverted participants prefer to recycle C&D waste may be due to their higher scores in openness compared with the conservatives.

5.1. Implications

This study not only identified the potential psychological factors driving tunnel construction managers to adopt effective waste management measures based on the TPB theory but also explored the variance of factors’ driving effects across four groups with different personality traits. Based on these findings, the government and construction enterprises can formulate targeted strategies to promote C&D waste management measures among the managers.

First, the influence of attitude and policies on the intention is significant and maintains a high and stable level across the four groups. This conclusion evidences the homogeneity in the relationship between psychological factors and managers’ intentions regardless of the personality profile and points out a common solution to effective C&D waste management. Consequently, targeted interventions such as training related to the economic and environmental benefits of effective waste management to alter attitudes towards waste management apply to all managers. Meanwhile, some measures like reducing waste rely on special construction plans and methods that feature resource efficiency, and developing relevant standards is required to provide a reference for the practitioners. Moreover, standards and markets for reused materials are also critical to promote the method of reusing construction waste, and this is beneficial to dispel the misgivings of the managers. Therefore, it is urgent for the government to formulate related policies to break down the barriers to the promotion of proper C&D waste management measures. In addition, the subjective norms seem to have a great impact on their intention, especially for the positives. This is because the cooperation between the construction managers and other participants, including design and development companies and the government, is quite close, and the impact is amplified for the positives who are more extroverted and agreeable. So, regular meetings and discussions related to dealing with waste are necessary to track the whole process of waste management, especially for the positives. Finally, decreasing the perceived behavioral difficulties of conservative and inverted managers would drive them to adopt effective waste management measures; thus, education regarding how to implement the methods is more suitable for them.

5.2. Limitations

There are several limitations to this research. First, this research adopts self-reported data on waste management intentions and behaviors, and thus the data might be impacted by the respondents’ social desirability [63]. However, this study tried to eliminate these adverse effects by stating that there were no correct or incorrect answers for all questions and that the data would only be used for scientific research, while assessments of the measurement and structural models were also strictly conducted to ensure the validity and reliability of the results. In subsequent research, multiple data sources, such as field observations, interview records, and actual waste management performance data, could be adopted to reduce the limitations of a single data source and enhance the credibility of the research results. Second, the research findings are currently applicable only to male tunnel construction managers, which could lead to the potential gender bias. In the following research, the psychological drivers of female managers could be discussed to eliminate the gender bias and improve the research conclusions. Meanwhile, to broaden the applicability of these results, participation from individuals in other fields is necessary. Third, this study only involves managers, due to their dominant role in waste management. Many people participate in the process of construction and demolition (C&D) waste management. This includes designers, who can optimize material use and construction processes to reduce waste, and construction workers, who are directly responsible for waste management. Their intentions on how to deal with waste are significant. Therefore, more investigation should be conducted to promote the development of the industry in terms of C&D waste management. What is more, this study focuses on the impact of various policies on the managers’ intention to implement effective C&D waste management measures instead of exploring the influence of one specific policy. However, investigating the influence of different policies is an important topic that could provide a reference for policymakers like the central and local governments. In the next stage of research, we will pay attention to this problem. Finally, only PLS-SEM was adopted to test the relationships between variables, and some other methods could be used to analyze the proposed hypotheses from other perspectives in subsequent research.

6. Conclusions

The research proposes an extended TPB model to explore tunnel construction managers’ intentions and behaviors regarding C&D waste management based on a sufficient sample. The results of the SEM analysis highlighted the strong predictive power of TPB constructs for managers’ intentions and behaviors. Additionally, policies and environmental concerns also played significant roles, while moral norms had a negligible impact.

The study divided the respondents into four groups based on personality characteristics and verified significant differences in the psychological attributes, as well as in waste management intentions and behaviors, among these groups. Generally, the positive and temperate participants outperformed the conservative and introverted ones in most psychological factors, as well as intentions and behaviors, due to high levels of extraversion, agreeableness, and conscientiousness. Meanwhile, the correlations between psychological drivers and waste management intentions and behaviors vary across different groups except for attitude and policies whose roles are stable and significant regardless of the personality traits. For the positives, subjective norms are the most effective driving factor in promoting effective waste management. Similar psychological drivers are observed for the temperate group. However, the impact of these drivers on temperate respondents is weaker compared to their impact on positives. Different from the positives and temperates, PBC and environmental concerns show a stronger relationship with the conservative and introverted participants’ intentions. The analysis and discussions in this study not only enhance our understanding of the relationship between psychological drivers and C&D waste management behaviors but also advance C&D waste management from a personality perspective. The findings are helpful in developing targeted and tailored interventions to encourage managers to adopt effective waste management measures to realize the goal of a circular economy.