Effect of water quality on the strength and durability characteristics of blended cement concrete silica fume concrete and fiber reinforced concrete

Abstract

Water is an important ingredient of concrete, which not only actively participates in the hydration of cement but also contributes to the workability of fresh concrete. Cement is a mixture of complex compounds, the reaction of cement with water leads to its setting and hardening. All the compounds present in the cement are anhydrous but when brought into contact with water they get hydrolyzed, forming hydrated compounds. Since water helps to form the strength giving cement gel, the quality of water is to be critically monitored and controlled during the process of concrete making. As water, universally the most abundant and naturally available solvent can contain a large number of impurities ranging from less to very high concentrations of them. In practice, very often, great control on properties of cement and aggregate is exercised, but the control on the quality of water is neglected. A popular yard-stick to the suitability of water for mixing concrete is that, if it is fit for drinking it is fit for making concrete. This does not appear to be a true statement for all conditions. Some waters, containing a small amounts of sugar would be suitable for drinking but not for mixing concrete and conversely water suitable for making concrete may not necessarily be fit for drinking, especially if the water contains pathogenic microbial contaminants. The concrete mixing water is generally required to comply with the standards of American society for testing and materials (ASTM) or with the Indian standards (IS 456-2000). The standards specified for various aspects of water do not represent the true picture of their purports on setting and strength development of concrete. Literature also confirmed structural deteriorations of several concrete components due to the usage of improper quality of water both in construction works as well as for curing purposes. Failure of many structural members is also reported due to constant contact of impure water with the concrete structures.