Weakness of Concrete :
i.Normal concrete has comparatively low tensile strength and for structural applications it is normal practice to incorporate steel bars to resist tensile forces. Tensile strength of concrete is approximately 10% of its compressive strength and is not reliable because of shrinkage cracks.
iii.Low ductility (brittle)
iv.Low strength to weight ratio
The ingredients of concrete are:
The type, quality, and proportioning of these ingredients affect the curing rate, compressive strength and durability of the concrete. Chemical admixtures can be used to enhance one or more properties of the concrete or to improve its handling and placing characteristics.