Performance of cement stabilized recycled aggregate base course added with metakaolin

Jianming Yao,Wei Wang,Xuyan Song

doi:10.1051/e3sconf/202234101009

Abstract

In order to better use the old cement concrete pavement materials in the cement stabilized base of the reconstruction or new road. In this paper, metakaolin was used to replace recycled fine aggregate with different proportions to prepare cement stabilized recycled aggregate base mixture, and the physical and mechanical properties and dry shrinkage properties of cement stabilized recycled aggregate base mixture were studied. The results of the study show that adding a proper amount of metakaolin can reduce the optimal water content of the mixture, increases the maximum dry density and 7d unconfined compressive strength of the mixture, and also reduces the total water loss and dry shrinkage of the mixture. The research results can provide new ideas for the recycling of road waste materials.

Highlights

Since the 40 years of reform and opening up, China has devoted all its manpower and material resources to civil engineering and greatly improved the quantity and quality of infrastructure
In order to explore whether metakaolin can improve the mechanical properties and drying shrinkage performance of cement stabilized recycled aggregate base, metakaolin was added to cement stabilized recycled aggregate base mixture with different contents, and the changes of physical and mechanical properties and drying shrinkage performance were studied
Five schemes are designed according to the C-B-1 gradation required by highways and first-class highways : the original base mixture ( G0 ), and the metakaolin is replaced by 1 %, 3 % and 5 % of the total mass of the mixture to replace the fine aggregate in the mixture, respectively represented by G1, G3 and G5

Summary

Introduction

Since the 40 years of reform and opening up, China has devoted all its manpower and material resources to civil engineering and greatly improved the quantity and quality of infrastructure. Cement stabilized base is a kind of base structure widely used in road in China because of its high stiffness, low cost and good construction performance. Due to the large amount of cement paste contained in recycled aggregate and the micro-cracks. Metakaolin is a mineral admixture made by calcining kaolin It contains a large amount of amorphous silicon dioxide and aluminum oxide. It has high pozzolanic activity and the function of filling the gap of cement paste, which can improve the mechanical properties of concrete significantly reduce its internal porosity [4,5]. In order to explore whether metakaolin can improve the mechanical properties and drying shrinkage performance of cement stabilized recycled aggregate base, metakaolin was added to cement stabilized recycled aggregate base mixture with different contents, and the changes of physical and mechanical properties and drying shrinkage performance were studied

Raw material

Test method

Physical and mechanical properties

Drying shrinkage

Findings

Summary