The Base Course Binder With High Added Ground Granulated Blast Furnace Slag

The kind of binder, construction condition, aggregate often cause two problems as follows when cement-stabilized mixture is use on the base course of the road: (1) the damage of the pavement caused by the shrinkage crack, (2) the inconvenrence of the work flow when the setting time is to short.The base course binder with high added Ground granulated blast furnace slag (GGBS) is studied to avoid such problems. Its formulation is 75% GGBS (including 2%~4% lime stone), 15% cement, 4% calcined gypsum and 6% lime hydrate. It is chosen according to the standard of compressive strength of cement mortars, the setting time and drying shrinkage after GGBS with different minerals and less cement with different content, According to the formulation, the standard of high compressive strength of cement mortars as Ordinary Portland cement 32.5(P O32.5) can be met, and construction time can be prolonged because of the following advantage of such formulation: short early drying shrinkage, greater later swelling, the initial setting time as long as four hours and half and the final setting time as long as nine hours.When the base course binder with high added GGBS is applied to the road test, we find that it has special requirement of the soil when it stabilize soil, the result show that the base course binder with high added GGBS is suitable for soil when 2% lime stone is put into GGBS. And the base course binder with high added GGBS is more suit for aggregate when 4% lime stone is put into GGBS. The cement stabilizing aggregate mixture including the base course binder with high added GGBS have higher compressive strength and flexural strength, crack coefficient, smaller compressive modulus, flexural modulus and better drying shrinkage coefficient than cement stabilizing aggregate mixture with P . O32.5.This paper used SEM, X-ray diffraction (XRD) to study mechanism of the base course binder with the high added GGBS hydration developing. The result show that thehydrate products of the base course binder with high added GGBS paste mainly include C-H-S and AFt, and have few Ca (OH) 2, with this, the base course binder with high added GGBS have high flexural strength of cement mortars and smaller drying shrinkage;Therefore, exchanging ion can be occurs between the binder with the activity component in soil. In the base course binder with high added GGBS stabilized -aggregate mixture, the hydrate products are similar with it of it's paste hydrate products, the content of C-H-S is higher than that in P ? 032.5...