Long term flexural behaviour of reinforced baked clay beams

Clay is a low cost and environment friendly material of construction. On firing, it becomes hard and attains the compressive strength as high as normal concrete. This paper presents the flexural behaviour of singly reinforced baked clay beams under long term sustained loads. The loads applied at mid span of these beams were 30%, 40% and 50% of their short term failure load for a period of 360 days. The results show that the rate of deflection, formation of cracks and their stabilization was completed in a certain period of time depending upon the intensity of long term sustained loads. In the first and second loading conditions, this period of opening and stabilization of cracks was 100 and 77 days, respectively. Then the deflection increased with decreasing rate. While in case of 50% of loading condition, the period of formation and stabilization of cracks was reduced to only 50 days and then these cracks became dormant and no new crack was developed with respect to time. After that negligible mid span deflection was observed with respect to time. In addition to this, the deflection in these beams was more compared to the estimated long term deflection according to ACI code.