Wastewater Reuse For The Application Of Concrete Mixing Water

The behaviors of secondary effluent and reclaimed water for mixing concrete are researched experimentally and systematically in this paper. The experiment tasks done are as follows: The characteristics of secondary effluent and reclaimed water are tested. The influence of secondary effluent and reclaimed water characteristics to cement ability and to concrete mixture ability and to concrete basic mechanical properties and to concrete admixture(water reducing) and to concrete ageing resistance ability and to cement mortar ability. The microcosmic structure of concrete is observed through SEM(scanning electron microscope). The mechanism, the concrete strength ability and ageing resistance ability are studied. At last, The behavior of secondary effluent and reclaimed water for mixing concrete are analyzed from the aspects of social benefit and economic benefit and environmental benefit and flexibility. The results of experiment showed that:Firstly, The characteristics of secondary effluent and reclaimed water meet the water for mixing concrete standard. Some water characteristic indexes reach the request of water for pre-stressed concrete.Secondly, The influences of secondary effluent and reclaimed water to cement ability are experimented. The results show that: The cement ability is not affected by comparison with the drinking water sample.Thirdly, The influences of secondary effluent and reclaimed water to the concrete mixture ability are not influenced. The effects of the concrete workability and construction properties are not obvious.Fourthly, The concrete basic mechanical properties (including ubic strength and compressive strength and the elastic modulus and tensile strength under bending) are enhanced a bit. However, the change belongs to the normal range.Fifthly, In adding concrete admixture(water reducing)condition, the concrete enhancing Strength of secondary effluent and reclaimed water is not changed. The characteristics of secondary effluent and reclaimed water is not relevant to the effect of concrete admixture.Sixthly, The concrete ageing resistance ability (including seepage of resistance freeze-thaw resistance) is not influenced. But the seepage of resistance is a little higher than the drinking water sample.Seventhly, The influence of secondary effluent and reclaimed water to cement mortar ability is a little different from the drinking water. However ,the deflection belongs to the standard of water for mixture concrete.Finally, In the microcosmic structure aspects, After 7d or 28d curing periods. The components and qualities of hydration products, the hydration process and the pore structure of reclaimed water concrete sample are similar with the drinking sample.