Next Article in Journal
An Ultrasonic Through-Metal-Wall Power Transfer System with Regulated DC Output
Next Article in Special Issue
Algorithm for Virtual Aggregates’ Reconstitution Based on Image Processing and Discrete-Element Modeling
Previous Article in Journal
Optimal Power Allocation with Hybrid Relaying Based on the Channel Condition
Previous Article in Special Issue
Fatigue Resistance Evaluation of Modified Asphalt Using a Multiple Stress Creep and Recovery (MSCR) Test
Article Menu
Issue 5 (May) cover image

Export Article

Open AccessArticle

Fatigue Equation of Cement-Treated Aggregate Base Materials under a True Stress Ratio

1
National Engineering Laboratory of Highway Maintenance Technology, Changsha University of Science & Technology, Changsha 410004, China
2
Inner Mongolia Communications Construction Engineering Quality Supervision Bureau, Hohhot 010051, China
3
Department of Civil and Environmental Engineering, Michigan Technological University, Houghton, MI 49931, USA
*
Author to whom correspondence should be addressed.
Appl. Sci. 2018, 8(5), 691; https://doi.org/10.3390/app8050691
Received: 4 April 2018 / Revised: 26 April 2018 / Accepted: 26 April 2018 / Published: 29 April 2018
  |  
PDF [5339 KB, uploaded 3 May 2018]
  |  

Abstract

The objective of this article is to establish a fatigue equation based on the true stress ratio for cement-treated aggregate base materials. The true stress ratio herein means the ratio of the stress and the true strength of the cement-treated aggregate base materials related to loading rates and curing times. The unconfined compressive strength tests and compressive resilience modulus tests were carried out under various loading rates and curing times of 3, 7, 14, 28, 60, 90 days, respectively. According to the test results, the relationship between the unconfined compressive strength (a mix design parameter in China) and the compressive resilience modulus (a structural design parameter and the construction quality control parameter in China) of the cement-treated aggregate base material with different curing times was established. However, it was found that the strengths varied with the loading rates, which is not reflected in the existing fatigue equations. Therefore, it is questionable to obtain the stress ratio of fatigue tests with a fixed strength value obtained from the standard strength test where the loading rate is fixed (in China, the fixed loading rate is 1 mm/min for cement-treated aggregate base materials). Thus, in this paper, the four-point bending strength (i.e., flexural strength) test was carried out at different loading rates to resolve such deficiencies. Based on the strength test results at different loading rates, the true stress ratio of the fatigue test corresponding to the fatigue loading rate can be calculated. Then the four-point bending fatigue test was conducted to establish an improved fatigue equation characterized by the true stress ratio. The results show that the patterns of variation for unconfined compressive strength increasing with the curing time were similar to that of the compressive resilience modulus. The fatigue equation curve based on the true stress ratio can be extended to the strength failure point of (1, 1), where both the true stress ratio and the fatigue life value are one. The internal relationship between the strength failure and the fatigue failure was unified. This article provides a theoretical method and basis for unifying the mix design parameters and the construction quality control parameters. View Full-Text
Keywords: cement-treated aggregate base; fatigue equation; loading rates; true stress ratio; flexural strength cement-treated aggregate base; fatigue equation; loading rates; true stress ratio; flexural strength
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Lv, S.; Liu, C.; Lan, J.; Zhang, H.; Zheng, J.; You, Z. Fatigue Equation of Cement-Treated Aggregate Base Materials under a True Stress Ratio. Appl. Sci. 2018, 8, 691.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Appl. Sci. EISSN 2076-3417 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top