C50 Acid Rain Corrosion Of Concrete Research

When the acid rain falls on the earth, the soil is degenerated, the lake is die, the forest is decreased and the building is corroded, even the health of human is threaten, The acid rain not only makes the surface of concrete change the color and desquamate, but also decreases the strength.Aim at the actuality of Foshan having serious acid rain corrosion, this paper confected the solution simulating the acid rain of Foshan, studied the influence of acid rain on the properties of concrete by measuring the index of compressive strength, the flexural strength, the property of adsorbing water and corrosion depth. Based on this research, the concrete resisting acid rain was applied in civil engineer, and the guide is advanced. The results are as following:1. During the corrosion of simulating acid rain solution, the color of mortar and concrete can change along with the time. At later time, the surface of specimens has white crystal when drying, and has the layered desquamation.2. The strength of mortar decreases with the increase of dry-wet cycle. By means of dry-wet cycle, the specimens containing 10％or 20％slag or 10％fly ash and 10％slag have higher strength and higher corrosion-resistance ratio and have best properties resisting acid rain compared to the control specimens.3. The specimens have created CaSO₄·2H₂O after dry-wet cycle, and the content of CaSO₄·2H₂O of control specimen is higher than that of specimen containing slag. The AFt does not be found.4. After 45 cycle of simulating acid rain corrosion, the mechanical properties of five kinds of mix can satisfy with the demand of the correlative criterion.5. The first damage of simulating acid rain on the C50 concrete is the layered desquamation of surface, the second is neutral and mechanical properties. The order of layered desquamation mass is FS-0, FF-1, FF-4, FSS-4, FP-0. After 45 cycles, the flexural strength of FF-0 decreases, and the compressive strength of FS-0 and FF-4 decreases too. The addition of slag or slag and fly ash can increase the later mechanical properties of concrete, and decrease the acid rain corrosion degree and speed of concrete. On condition of acid rain corrosion, the mechanical property sensitivity to surface status has clearly decrease.