Use of construction waste to modify soil grading for compressed stabilized earth blocks (CSEB) production

Abstract

Earthen materials have been used in civil engineering construction worldwide with different forms, such as mud, adobe, rammed earth and bricks. Compressed stabilized earth blocks (CSEB) can be considered as a new member of the earthen building material family. Also, it can overcome the problems associated with fired bricks and cement blocks. Cement is the most commonly used as stabilizers to enhance the properties of CSEB. The governing factor which controls the properties of CSEB is the amount of clay content in the soil. Researches have concluded that about 25% of clay and silt (finer) content contributes to high compressive strength. However, controlling of larger particles is not addressed much. This study focused on controlling the finer content as well as larger particles with the use of construction waste (mostly with crushed concrete) and river sand. Selected soil was modified to get the finer content as 5%, 10%, 15% and 20%. This modification was done by adding river sand and construction waste to the soil to optimize the particle packing based on particle packing theories. Cement was used as the stabilizer with 6%, 8%, and 10%. (150 × 150 × 150) mm3 cubes were cast and tested for dry density, water absorption, 28 days wet and dry compressive strength, accelerated erosion and compared with SLS 1382; part 2 requirements. Block properties were conformed with SLS 1382 requirement when finer contents are 10% and 5% with 10% and 8% cement. Further, Industrial-scale blocks of (350 × 100 × 175) mm3 made with 10% finer and 8% cement satisfied the Grade 1 block properties. CSEB made mixing with construction waste contributes to manage the environmental pollution due to construction waste while giving a fair solution to the problem with the shortage of building materials.