Analysis and improvement of physical and mechanical properties of burnt day bricks used in Rwanda

Abstract

In Rwanda, the construction industry faces a shortage of quality building materials, particularly local clay bricks, due to negligence and poor mixing methods in manufacturing process. this leads to delays and added cost in construction and negatively impact the local economy. the low quality of local clay brick is caused by issues such as near surface clay with high level of salt and sand, the use of dirty water and uneven burning. the study analyzed the defect of local clay bricks, designed and manufactured improved high quality clay brick and conducted a comparative study of physical and mechanical properties of local and improved clay bricks. Various technique, methods, and procedure of different test including site and laboratory test such as compressive test, water absorption test, hardness, soundness, size, shape and color were conducted. The result showed that average compressive strength (). The soundness test results indicated that improved clay brick produced a clear, ringing sound indicating good quality and unsuitability for construction. The hardness test result showed that local clay brick had lower indentation depth indicating higher resistance to wear and abrasion, while improved clay bricks had higher indentation depth indicating lower resistance abrasion. The result showed that improved clay brick had better physical and mechanical properties, including higher compressive strength, lower water absorption, and clear, ringing sound indicating good quality, than the local clay bricks. The research concludes that the improved clay bricks are more suitable option for the construction industry in Rwanda and recommend that the construction engineer pay more attention to surface preparation and sample mixing when manufacturing local clay bricks to improve their quality and prevent defects.