INFLUENCE OF MATRIC SUCTION AND SATURATION ON COMPRESSIVE AND FLEXURAL STRENGTH OF UNSTABILIZED COMPRESSED EARTH BLOCK

Abstract

Earth materials have been used as a construction material for centuries. But systematic modern research for compressed earth dates back to the early 60’s. Compressed earth has shown to be a very durable material. This is evident from all the ancient structures, which have stood the test of time. Previous experiments with compressed earth have studied the properties of compressed earth blocks. This research builds on that knowledge to study influence of matric suction and initial moisture content on the compressive and flexural strengths of the blocks.

The soil was procured from a landfill site near Lubbock international airport. Tests were performed to analyze the soil type. Blocks were then made using the compressed earth block manufacturing machine available at Texas Tech University. Experiments were carried out to study the compressive and flexural strengths of the blocks when cured in two different relative humidity conditions. These blocks were made at three different initial moisture contents. The results show an increase in compressive strength with an increase in suction. The results for the flexural strength data were different from expected, showing a decrease in flexural strength with an increase in matric suction. The change in the strength was also studied relative to the change in the suction and saturation.