Effect of Reinforcement on Deflection and Cracks in Baked Clay Beams Subjected to Impact Loading

Abstract

Attempts are being made to utilize Reinforced Baked Clay (RBC) as a substitute of Reinforced Cement Concrete (RCC) for construction of low cost houses in plains of Pakistan. Since baked clay is considered to be more brittle as compared to concrete. Therefore, it is necessary to investigate how deflection and crack width of RBC beams subjected to impact loading are governed by amount of reinforcement. This paper presents the behaviour of RBC beams under drop weight impact loading. The beams were reinforced with two steel bars, one in compression zone and the other in tension zone. In group A beams, the diameter of steel bars was 12.7 mm, while the beams of group B were reinforced with steel bars of 15.8 mm diameter. The RBC beams were subjected to repeated impacts of a hammer of mass 21 kg falling from a height of 1000 mm. The results show that 1) three times reduction in deflection, and 2) 2.5 times decrease in crack width, were achieved in RBC beams by increasing the area of steel to 50%. In addition to this, all the RBC beams failed within nine blows of the hammer, irrespective of area of reinforcement.

Flexural Behaviour of Partially Prestressed Reinforced Baked Clay Beams

“…The studies suggest that in addition to firing temperature [5][6][7][8][9], compression applied during casting of beams [10] plays an important role in increasing compressive strength of baked clay. The structural properties of RBC beams were investigated in terms of compressive strength [11], modulus of rupture [12], and load versus deflection response under static loading [13][14][15][16][17][18][19] and impact loading [20,21]. The problems of shrinkage and cracking of clay beams during dying [22] and firing process [23] are also addressed.…”