Research On Value Of Strength And Modulus Of Cement-stabilized Crushed Rock For Pavement Base Course

Cement stabilized crushed stone is widely used as pavement base materials, and the reliability of material parameters has significant influence on the study of pavement structure behavior, performance prediction, thickness design and so on. In the design of domestic highway pavement design, the basic material parameters are determined by testing on site or querying specification tables, and mainly depending on the latter. The lack of reliability of material parameter value is caused by the wide range of material parameters recommended by the current specification, together with the large-range fluctuation and obvious dispersion of the large amount of existing test data. Therefore, based on a large number of existing test data and a certain degree of reliability, the paper studies the parameters of cement stabilized crushed stone materials, in order to provide more reliable parameters for the research and the design of the pavement surface.This study selected the compressive strength, splitting strength, flexural strength, and compressive resilient modulus of the cement stabilized crushed stone as research object and cement dosage, curing period, gradation type and the molding methods as the main influencing factors by collecting and analyzing the experimental data. The experimental data was classified layer by layer according to four main influencing factors, then outliers of the data was judged and eliminated according to the Pauta(3Δ) Criterion. Based on the normality hypothesis testing results of the experimental data, the represent values at different reliability(90%, 95% and 97%) were calculated and compared with high-level literature test data. As a result, the representative values of compressive strength and compressive resilient modulus were under 97% guaranteed rate while the representative values of splitting strength and flexural strength were under 90% guaranteed rate. The relationship between the four influencing factors selected above and the representative values were analyzed and verified to comply with the experimental results. With the revise of correction coefficient of the molding method and gradation type, the relations between the representative values and cement dosage or curing period were established based on mathematical and statistical regression methods. By comparing the accuracy of different relations, establish value models of compressive strength, compressive resilient modulus, splitting strength and flexural strength of the cement stabilized crushed stone and provide reference for the pavement structure design and performance estimates.