Selection of Strength Standard of CTB in High-Class Highways

2011 ◽  
Vol 243-249 ◽  
pp. 4261-4264
Author(s):  
Yin Fei Du ◽  
Xin Yu

A reasonable design strength standard is of great practical significance for reducing pavement diseases. First, the bottom layer tensile stress of the typical pavement structure in the operating period is calculated using computer program BISAR while the overload、the interface link status and construction variability are all considered. And then the bottom layer tensile stresses of the upper and lower base are checked under truck load during construction. According to the relationship between cleavage strength (90d) and unconfined compressive strength (7d), it is deemed that the appropriate design strength standard should be 2.1MPa~3.5MPa. Finally, combined with the results of the unconfined compressive strength of core samples in the field it is proved that the current design standard is a little high.

2019 ◽  
Vol 814 ◽  
pp. 399-403
Author(s):  
Anuchit Uchaipichat

This paper presents the relationship between the dynamic cone penetration (DCP) test results and the unconfined compressive strength of lateritic cemented soils. A series of DCP tests and unconfined compressive strength was performed on lateritic cemented soil. The soils sample used in this study was lateritic soil. The test results for the DCP tests are presented in terms of penetration index. It can be observed that the penetration index decreased with increasing curing period and cement content. Moreover, the unconfined compressive strength of cemented soils increased with curing period and cement content. The relationship between unconfined compressive strength and penetration index is presented. A unique relationship for unconfined compressive strength can be obtained.


2019 ◽  
Vol 31 (4) ◽  
pp. 966-972 ◽  
Author(s):  
Husam H. Alkinani ◽  
Abo Taleb T. Al-Hameedi ◽  
Shari Dunn-Norman ◽  
Ralph E. Flori ◽  
Steven A. Hilgedick ◽  
...  

2011 ◽  
Vol 255-260 ◽  
pp. 4012-4016
Author(s):  
Jun Qing Ma ◽  
You Xi Wang

This paper studies relationship between soil-cement parameters and unconfined compressive strength. The research in tensile strength and deformation modulus of soil-cement is an important basis for soil-cement failure mechanism and intensity theory. They also impact cracks, deformation and durability of cement-soil structure. Shear strength and deformation of soil-cement is important to the destruction analysis and finite element calculations. Therefore it needs to study on tensile strength, shear strength and deformation modulus of soil-cement. Based on previous experiments, the relationship of tensile strength, shear strength, deformation modulus and unconfined compressive strength of soil-cement are quantitatively studied.


2021 ◽  
Vol 9 ◽  
Author(s):  
Bin Tang ◽  
Biaohe Zhou ◽  
Liang Xie ◽  
Jianfeng Yin

Thixotropy is a hot topic in the field of rheology of dispersed systems. Studying the quantitative index and evaluation method for thixotropy of clay is of great significance to evaluate the safety of foundation under long-term load. To explore the index system and classification methods for the thixotropy of clay, unconfined compressive strength tests were carried out on three groups of undisturbed soil and remolded soil that were cured at different times after remodeling of the Zhanjiang Formation in China to obtain the unconfined compressive strength values of the samples and establish the relationship between unconfined compressive strength and curing time of the remodeled soil. The concept of thixotropic sensitivity is introduced to reflect the relationship between thixotropy and structure. According to the relationship between thixotropy sensitivity and curing time and its logarithmic value, two indexes of structural recovery coefficient K and structural recovery index Ke were established to evaluate the thixotropy of structural clay in the Zhanjiang Formation. Following the structural classification method of soil, the boundary values of structural recovery coefficients KI and KII are calculated to classify the thixotropy of soil. When the value of K is less than that of KI, the thixotropy of soil is weak. When the value of K is greater than that of K but less than that of KII, the thixotropy of soil is moderate. When the value of K is greater than that of KII, the thixotropy of soil is strong. The method is used to discuss the thixotropy of soil in the literature, and the rationality of the method is verified. Results show that this method can be used to preliminary classify the thixotropy of soil.


2014 ◽  
Vol 548-549 ◽  
pp. 228-232 ◽  
Author(s):  
Xiao Chen ◽  
Ji Wei Liu ◽  
Ming Kai Zhou

To improve the impact of fly ash on the properties of cement-fly ash stabilized crushed stone, and promote it popularize and apply better. This paper investigated the effect of fly ash content on unconfined compressive strength, cleavage strength and resilient modulus of cement-fly ash stabilized crushed stones, and those relationships between mechanical parameters. The results showed that with increasing of the fly ash content, the unconfined compressive strength and cleavage strength increased at first, then decreased, the resilient modulus decreased, and The brittleness index increased. We can conclude that the optimal fly ash content is between 10% and 15%, and increment of fly ash content can improve its crack-resistance.


2010 ◽  
Vol 168-170 ◽  
pp. 1881-1885
Author(s):  
Xiao Chen ◽  
Ming Kai Zhou ◽  
Jia Liu

This paper investigates the effect of fly ash content on unconfined compressive strength, cleavage strength and resilient modulus of cement-fly ash stabilized crushed stones. The relationships between mechanical parameters were also studied. The results show that with fly ash content increasing, the unconfined compressive strength and cleavage strength were increasing firstly but decreased then, and the resilient modulus were decreasing. The brittleness index was increased by the increment of fly ash content. It can be concluded that the optimal fly ash content in cement-fly ash stabilized crushed stones is between 10% and 15%, and increment of fly ash content can improve its crack-resistance.


2013 ◽  
Vol 668 ◽  
pp. 48-52 ◽  
Author(s):  
Chuan Yi Zhuang ◽  
Ya Li Ye

On the basis of test analysis, mix design of cement stabilized gravel powder, cement stabilized gravel powder mixed with 20% aggregates and cement stabilized gravel powder mixed with 40% aggregates were compared, their unconfined compressive strength were tested, and the mixed aggregates ratio and mix design were ultimately determined. The experimental results show that mixing a certain amount of aggregate can reduce cement dose and meet the design strength. Engineering project cost by mixing with a certain amount of aggregate was little higher than that of cement stabilized gravel powder. Comprehensively considering technical and economic factors, the recommended amount of aggregates mixed with 30% and cement dose of 2%.


Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 302
Author(s):  
Yaxu Liu ◽  
Zhuang Liu ◽  
Erwin Oh ◽  
Dominic Ek Leong Ong

The study of the strength of reconstituted and stabilised soft soils is very important in geotechnical engineering. The soil particles, such as clay, sand, and silt play important roles in determining the behaviour of soils. The behaviour of clay and sand particles are unique; however, the behaviour of silt particles lie in a transitional form between sand and clay. Therefore, this paper seeks to investigate (a) the effect of silt contents on the strength of soft soils; (b) the effect of silt content on the strength of cement-stabilised soft soils; and (c) the microstructure of the soft soil specimens stabilised by cement with varying particle size distribution. A series of tests consisting in consolidated, isotropic undrained (CIU) triaxial tests, unconfined compressive strength (UCS) tests, and scanning electron microscope (SEM) images were conducted in this study to achieve these objectives. In conclusion, the relationship between the silt content and critical state behaviour of soft soils (both clay and silt particles) are proposed. For the cement-stabilised specimens, the unconfined compressive strength increases with the increase in silt content when the cement content is 10%. However, the UCS decreases with the increase in silt content when cement content is 30%. With cement content ranging from 15–25%, the UCS increases at first with the increase of silt content but decreases once the silt content reaches a ‘saturation’ point.


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