2.1. Sustainable Construction
As construction projects tend to be large-scale and long-lasting undertakings, they have a profound impact on the economy, environment, and society [
21]. Lack of sustainability in construction may result in environmental damage including massive consumption of non-renewable natural resources, production of solid waste, noise, gas, and water pollution. Hence, sustainable construction management is of vital importance.
A large number of sustainable construction studies have focused on sustainable building [
22,
23,
24], which is mainly concerned with the planning and design phase of construction. Sustainable building refers to architecture designed according to a sustainable development concept that aims to reduce energy consumption and pollution, improve resource conservation, and protect the environment. Merino et al. [
25] summarized different alternative uses of demolition waste generated by construction projects and proposed various measures and strategies to improve the processing of this waste. Gutierrez and Lee [
26] summarized techniques for optimizing and integrating sustainability-related functions in building design and discussed the advantages and benefits of these functions.
Another group of studies focused on macro-level sustainable construction, including sustainability assessment [
27], best practices for sustainable construction [
7,
8], policy implementation [
28], and investigations of driving factors [
29]. Pitt et al. [
30] explored the best practices and promotion of sustainable construction and suggested that the government or the project owner could promote the implementation of sustainable construction by setting financial rewards or penalties. She et al. [
31] investigated the main factors hindering the sustainable development of infrastructure in southwest China and revealed four main hindering factors—“Economic Capacity,” “Governance and Management,” “Policy Instrument and Public Participation,” and “Local Geographic Characteristics.”
2.2. Project Citizenship Behavior
In order to capture an individual’s work behavior that contributes to organizational effectiveness, “Organizational Citizenship Behavior” (OCB) was initially proposed. Early OCB researchers regarded citizenship behavior as being separate from in-role job performance and emphasized the idea that OCB should be viewed as both extra-role and organizationally functional [
32,
33]. According to their understanding, the OCB was defined explicitly as “individual behavior that is discretionary, indirectly or not explicitly recognized by the formal reward system, but in the aggregate promotes the effective functioning of the organization.” [
33] However, Graham [
34] argued that previous definitions required scholars to distinguish in-role work from extra-role work, which is an inconsistent distinction that varies across individuals, job types, and organizations. To eliminate the inconsistency, he conceptualized OCB as a global notion that includes all positive in-role and extra-role behaviors of individual members of an organization. As this broader conceptualization provides a more theoretically grounded and comprehensive definition of OCB [
35], has been adopted in this paper.
However, studies on dimensions of specific PCB are quite limited [
17,
36,
37]. As PCB is the citizenship behaviors conducted by individuals in projects-based organizations, we reviewed the literature on citizenship behaviors and explored the research trend of its dimensions (see
Figure 1). At the very beginning, scholars mainly focused on the general citizenship behavior in permanent organizations, and the initial division into dimensions was not specific. For example, Williams and Anderson [
38] divided OCB into two dimensions, namely, organization-directed OCB (OCB-O) and individual-directed OCB (OCB-I). Later, dimensions that were more specific were defined by scholars. Podsakoff et al. [
39] examined the literature on the OCB and other related constructs, and divided OCB into seven dimensions: (1) helping behavior, (2) sportsmanship, (3) organizational loyalty, (4) organizational compliance, (5) individual initiative, (6) civic virtue, and (7) self development. These dimensions were later widely used by scholars working in this research area.
As the depth of research went further, interest in organizational citizenship behaviors expanded from the field of organizational behavior to a variety of domains, including network citizenship behavior [
17], and inter-organizational citizenship behavior [
40]. Considering that citizenship behavior may not only exist in permanent organizations, scholars started to investigate citizenship behavior in some typical provisional organizations, such as projects [
17] and teams [
41]. One strand of this line of research was studies of project citizenship behavior (PCB) and its potential influence. Considering projects as temporary organizations, Braun and his colleagues [
17] originally re-conceptualized OCB as PCB based on their exploratory study, and proposed the definition and dimensions of PCB. Project-specific helping behavior, project loyalty, project compliance, and project-proactive behavior were the four dimensions identified in their research. As these dimensions are similar to the dimensions of general OCB, we can regard PCB as an extension of OCB in the project context. In the same vein, several empirical studies about the antecedents and consequences of PCB were conducted. Ferreira et al. [
36] explored the relationship between citizenship behavior and project managers’ performance in a comparative context of German and Portuguese project managers. Xia et al. [
37] examined how work–family conflict could influence PCB among Chinese project managers.
In the present study, we focus on four dimensions of PCB among managers, including helping behavior, project compliance, individual initiative, and taking charge. PCB is a comprehensive construct, with several dimensions consisting of several specific behaviors. However, the most typical dimension of PCB [
39] is helping behavior, which has been identified by almost every scholar working in this area, and refers to proactive behavior directed at helping other team members finish their work or solve problems. As a construction project is team–based and time–limited, team members may actively take on work beyond their job responsibilities, or assist other team members who are under time pressure, which may help to improve the project performance. Project compliance is an extension of organizational compliance in the project context. This dimension has been studied for a long time in the citizenship behavior area and was defined as “generalized compliance” by Smith et al. [
42], as “organizational obedience” by Graham [
34], and as “following organizational rules and procedures” by Borman and Motowidlo [
43]. It appears to capture an individual’s internalization and acceptance of the rules, regulations, and procedures, which results in scrupulous adherence to them, even when no one is observing or monitoring them. The reason why compliance is regarded as citizenship behavior is that, although everyone is expected to obey regulations, rules, and procedures at all times, many employees simply do not do so. Therefore, an employee who religiously obeys all rules and regulations, even when nobody is watching, is regarded as an especially “good citizen.” These two dimensions are identified by many scholars as affiliative behaviors, which are cooperative in nature and generally noncontroversial [
35]. Therefore, they have been selected as indicators for PCB in this paper.
In contrast to affiliative behaviors, challenging behaviors are citizenship behaviors through which employees express constructive criticism of the status quo for the purpose of creating improvement via changes [
44]. As a typical challenging behavior capturing wide-spread attention, personal initiative refers to behaviors aimed at ensuring the achievement of the project’s objectives, which may even exceed formal job requirements and may result in the improvements in processes, products, or services [
39]. Another kind of challenging behaviors is “taking charge,” which refers to the voluntary and constructive efforts by individual employees to effect organizationally functional change with respect to how work is executed [
45]. However, challenging behaviors may be considered aggressive by some team members and may lead to mixed outcomes [
46,
47]. For example, one experienced team member may discover latent risks and then give advice to the project manager or directly take actions to reduce it, but these actions may be somewhat offensive to his supervisors and colleagues.
2.3. Relationships between PCB and Construction Sustainability Performance
According to present studies in the OCB area, citizenship behaviors serves to promote the productive efficiency of permanent organizations, strengthen the cooperation and communication within the organization, increase organizations’ financial performance, and enhance the risk management capability of the organization [
39]. As sustainability is a higher expectation for project members, and PCB has something in common with OCB, the same pattern of influence may exist between PCB and project sustainability. In order to measure the sustainability level of a construction project, the concept of sustainability performance should be clarified. It can be defined as implementing the construction project while meeting the needs of all stakeholders and satisfying their aspirations for a better life without compromising the life quality of future generations [
48]. Similar to corporate sustainability performance [
49,
50,
51,
52], construction sustainability performance also requires the balance among social development, economic development, and environmental sustainability.
In the past decades, a great deal of research has been done on the assessment of sustainable performance of construction projects and contractor activities [
21,
53,
54,
55]. Trufil and Hunter [
56] developed a framework for small and medium contractors to evaluate their sustainability performance via four dimensions, including economic, environment, social and processes. Chen et al. [
57] identified 33 sustainable performance criteria (SPC), based on the triple bottom line and the requirements of different project stakeholders, and grouped SPCs into seven dimensions. Shen et al. [
58] divided a project life cycle into five major processes, and developed a project sustainability performance checklist with a total of 112 indicators.
Nevertheless, it might be quite difficult to evaluate the sustainability performance of a construction project on the basis of such large number of indicators [
59]. Thus, composite indicators might be a better way to evaluate sustainable performance. Therefore, four composite indicators have been selected to depict the outcomes of a construction project from the perspective of sustainability, with a view to investigating whether PCB can improve sustainability performance in construction projects.
The “iron triangle” (cost, time, quality) is widely acknowledged as the most important goals in the implementation of construction projects. A project is considered successful if it is completed on time, within budget and meeting the required quality standards specified by the client [
60].
As mentioned above, the concept of sustainable performance has been extended from purely environmental concerns to also include those related to social and economic issues, which made “cost” an essential indicator of economic sustainability. Almost all studies on sustainability assessment have taken cost as a proxy indicator [
61,
62,
63,
64]. According to Shen et al.’s checklist [
58], indicators related to cost or budget appeared in all the five processes, and accounted for a large proportion of all indicators. Ugwu and Haupt [
61] took direct cost and indirect cost as indicators for economic sustainability. Keeble et al. [
62] defined the economic sustainability principle as whether the project can generate prosperity and enhance the affected economies and identified investment, tax, and profitability as detailed indicators.
Meanwhile, finishing the project on time will enhance the sustainability performance of the construction project to some extent. As sustainability requires environmental protection, social development, and economic development, we will explain the link between “on-time” and project sustainability performance from these three aspects. According to multiple literature, various kinds of pollution act as important indicators for environmental sustainability [
59,
65,
66]. Wijethilake [
65] considered reduced environmental impacts of production processes and reduced waste as indicators for environmental performance, and investigated ways to translate proactive sustainability strategy into corporate sustainability performance. Sixteen indicators, including specific effluent load, specific hazardous waste generation, and average noise level in the periphery, were identified by Singh et al. [
59], showing that the environmental sustainability performance level could be evaluated based on these indicators. However, as these pollution and waste are the inevitable product resulting from construction work [
66], meeting the pre-set schedule can reduce the duration of different kinds of pollution (noise, air pollution, water pollution, etc.) and waste that may be generated during the process of mechanized construction, and improve the environment protection. Meanwhile, meeting the schedule can also reduce the negative influence of the construction process to nearby residents and communities. The duration of above-mentioned pollution and the inconvenience brought by the construction will both decrease, which may improve the social development. Besides, finishing the project on time can also reduce the amount of overhead cost and provide a higher opportunity for the project to generate revenue at an earlier stage [
67] and benefit the economic development.
In the construction industry, the concept of “quality” demands the fulfilment of both explicit and implicit requirements, and needs to be assessed from the perspectives of both the product and the process. In this regard, the scope of quality should extend to more comprehensive level, which also encompasses sustainable performance [
68]. Kibert et al.’s study [
69] introduced seven principles to evaluate sustainable construction performance, among which providing quality products played a vital role. Chen et al. [
57] conducted a factor analysis and revealed that sustainability performance indicators can be grouped into seven dimensions, one of which was “quality.” Achieving the quality goal can help to decrease the possibility of the need for future refurbishment and consequent waste of resources, contribute to the quality of human life, and offer long-term benefits to all stakeholders.
Since the “iron triangle” is highly relevant to the issue of sustainable construction, and the objectives of schedule, cost and quality are usually stated clearly, we chose time, cost, and quality as the fundamental indicators to measure the sustainable performance of the construction project.
Besides, as there has been a long absence of the human factors in the debate on sustainability performance [
70], the efficiency of human resources is taking into account in this paper, as an indicator of construction sustainability performance. Since construction projects are mostly one-off temporary organizations, the project team only exists for a certain period and will be dismissed after the project. However, the cooperative and personal relationships among team members are a resource that can be “recycled” by cooperation in future projects. Suprapto et al. [
71] proposed that another important criterion for evaluating a construction project is whether the participants have the intention to seek for opportunities to cooperate in the future. Therefore, this paper regards cooperation in the future as an important means of resource conservation, and defines relationship sustainability as the indicator. Specifically, the individual’s proactive behaviors are regarded as the human resource input in the implementation of construction projects; the project performance and cooperation relationships are the outcomes for evaluating the sustainability performance, while the upcoming cooperation in the future can be considered as the cyclic utilization of human resources.
Based on the above arguments, we propose the following hypotheses:
Hypothesis 1. Project citizenship behavior—helping behavior (H1a), project-based compliance (H1b), taking charge (H1c), and personal initiative (H1d)—will promote construction sustainability by realizing the objective of quality.
Hypothesis 2. Project citizenship behavior—helping behavior (H2a), project-based compliance (H2b), taking charge (H2c), and personal initiative (H2d)—will promote construction sustainability by realizing the objective of cost.
Hypothesis 3. Project citizenship behavior—helping behavior (H3a), project-based compliance (H3b), taking charge (H3c), and personal initiative (H3d)—will promote construction sustainability by realizing the objective of completion according to schedule.
Hypothesis 4. Project citizenship behavior—helping behavior (H4a), project-based compliance (H4b), taking charge (H4c), and personal initiative (H4d)—will promote construction sustainability by increasing team members’ relationship sustainability (desire for future cooperation with team members).
According to the current research, the repetition of tasks will hinder the generation of citizenship behaviors. Scholars have found that repetitive tasks may seem easy and boring to team members. Thus, if they are asked to perform repetitive tasks, their motivation to engage in proactive behaviors may be low. Similarly, if the task is easy and repetitive, proactive behavior may be less significant in promoting the completion of the task. In the sustainable construction context, construction projects are of different sizes, technical requirements, and levels of complexity, and these differences may act as moderators between PCB and construction sustainability performance. With this in mind, we introduce project complexity into our study, and propose the following hypothesis:
Hypothesis 5. Project complexity acts as a moderator between PCB behavior and construction sustainability performance.
The hypotheses we listed above are shown in
Figure 2. This model illustrates the relationships among project citizenship behavior, sustainable construction performance, and project complexity.