Strength development of cement-treated sand using different cement types cured at different temperatures

Lanh Si Ho,Kenichiro Nakarai,Minoru Morioka,Kenta Eguchi,Takashi Sasaki,P Hajek,R Sriravindrarajah,B.S Gan,A.L Han,S Kristiawan,W.T Chan,B.A Hidayat,M.B Ismail

doi:10.1051/matecconf/201819501006

Abstract

This study aimed to investigate the strength development of cement-treated sand using different cement types: ordinary Portland cement (OPC), high early strength Portland cement (HPC), and moderate heat Portland cement (MPC) cured at different temperatures. The cementtreated sand specimens were prepared with 8% of cement content and cured under sealed conditions at 20οC and 40οC, and mortar specimens were also prepared for reference. The results showed that the compressive strength of cement-treated sand increased in order of MPC, OPC, and HPC under high curing temperatures. It was interesting that the compressive strength of the specimens using HPC was much larger than that of the specimen using OPC and MPC under 20οC due to the larger amount of chemically bound water. Additionally, it was revealed that under high curing temperatures, the pozzolanic reaction was accelerated in the cement-treated sand; this may be caused by the high proportions of sand in the mixtures.

Highlights

Cement-treated soils have been applied popularly for soft soil improvement, especially for the deep mixing method
To evaluate the effect of curing temperature on strength development of mortar and cement-treated sand using different cement types, the compressive strength ratios of mortar and cement-treated sand are shown in Figs. 1 to 3
For the case of moderate heat Portland cement (MPC), the compressive strength ratios were larger than those in ordinary Portland cement (OPC) and high early strength Portland cement (HPC) for both mortars and cement-treated sand, and the ratios were even greater than 1.0 at 91 days. This may be related to MPC minerals that contain more C2S, which can reduce the negative effect of high curing temperatures

Summary

Introduction

Cement-treated soils have been applied popularly for soft soil improvement, especially for the deep mixing method. The strength development of cement-treated soils is governed by many factors such as conditions of soil, mixing, and curing [4]. In terms of curing conditions, the curing temperature is an important factor that affects the strength development of cement-treated sand. It implies that the core of the deep mixing column was subjected to high temperatures. This high temperature may promote the hydration and pozzolanic reaction process

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Results

Conclusion