Civil Engineering Department, College of Engineeri, Universiti Tenaga Nasional
The demand for sustainable alternative construction materials to cement in modern technology cannot be underemphasized. This paper presents a non-fired green brick with an agriculture residue namely, rice husk. Although, high plasticity brown clay deposits are widely distributed in Malaysia and rice husk is a well known agriculture residue, research works on non-fired green brick with rice husk are relatively scarce. This research aims to investigate the strength development in non-fired bricks containing various amounts of rice husk. To achieve such aim, compression and flexural tests were conducted to evaluate compressive and flexural strengths of non-fired bricks. A series of brick specimens were cast with varying rice husk percentages. The test specimens were naturally sun dried. The effects of rice husk percentage (9-15%) and drying age (1, 7, 14, 21, and 28 days) on Atterberg limits; compressive strength; water absorption and flexural strength were investigated. The results indicate that, 12% rice husk is the optimum content to reach maximum 28-day compressive and flexural strengths of 10.4 MPa and 3.5 MPa respectively. The results further showed that rice husk higher than 12% leads lower strength than control bricks for all the ages. In summary, it has been observed that rice husk enables a rapid strength development, enhancing the compressive and flexural strengths of the bricks. The results developed in this research work can contribute a cost-effective design of non-fired green brick as a sustainable building material.