ABSTRACT: The effect of water to binder(wb) ratio. paste content. type of cement. content of mineral aggregate maximum size(G sand content, and presence of moisture on the tensile strain admixtures, capacity. or cracking strain. of concrete were investigated using flexural test method. The investigation showed that the effect of cement type. paste content and sand content in the tested ranges was not significant The cracking strain decreased with the increase of the wb ratio, and replacement ratio of fly ash and limestone powder. For ground granulated blast-furnace slag(GGBS). specimens containing 30% and 50% GGBs showed a higher cracking strain than that without GGBs. but at 70% GGBs. the cracking strain decreased. The cracking strain concrete with a high w/b ratio(wb-0.55) was the highest when G was 19 mm. However, when wh ratio was 0.30. there was a tendency that the cracking strain was the highest when Gas was 10 mm. The cracking strain increased whereas the flexural strength and splitting tensile strength reduced when concrete was oven-dried KEYWORDS Tensile strain capacity. Cracking strain, Flexural strength. Fly ash.slag. Limestone powder. Moisture