Soil characterization for adobe mixtures containing Portland cement as stabilizer

ABSTRACT One of the most economical ways to build with soil is to use adobe technique. There are several types of soils and most of them are not suitable for using to construct buildings. Physical and chemical characteristics of the soils will influence on its performance to use for buildings. This work aims to characterize physically, chemically and mineralogically two soil samples and study the dosage of mixtures for adobe using Portland cement as stabilizer. It was studied three different Portland cement content (6%, 9% and 12%) in the soil. The results showed that compressive strength of up to 5 MPa at 28 days for both type of soils studied with 12% of Portland cement. In addition, a comparison between two methods used for the particle size analysis of the soils. It was observed that the results differed in each method analysis. Overall this work has shown that to use these soils for adobe bricks, 9% of Portland cement is enough to reach the minimum compressive strength required by standard. Furthermore, this research brings results about the determination of the clay content of the soil, indicating that the traditional method to determine the size distribution curve by sieving and sedimentation may not be the most suitable to check this clay content.

摘要：以土坯（adobe）技术开展土木建造是最为经济的土壤利用途径之一。土壤品类繁多，其中多数不适用于建筑工程。土壤的物理与化学特性会直接影响其建筑应用性能。本研究旨在从物理、化学及矿物学层面表征两组土壤样品，并探究以硅酸盐水泥（Portland cement）作为稳定剂的土坯混合料配比。试验设置了三组不同的硅酸盐水泥掺量（6%、9%及12%）开展土壤性能测试。结果显示，当硅酸盐水泥掺量为12%时，两组供试土壤在养护28天后的抗压强度均可达到5 MPa。此外，本研究对比了两种土壤粒径分析方法，发现不同分析方法所得结果存在显著差异。综合来看，若将该类土壤用于制作土坯砖，掺入9%的硅酸盐水泥即可满足标准规定的最低抗压强度要求。此外，本研究还开展了土壤黏土含量测定相关试验，结果表明，传统的筛分-沉降法绘制粒径分布曲线的方式，或许并非测定该类土壤黏土含量的最优方案。