Industrial grade sodium tripolyphosphate has a good inhibitory effect on the slump of the concrete mixture
The slump of the concrete mixture during the construction process is a relatively common loss. In order to better avoid and reduce the loss caused by the slump of the concrete mixture, industrial grade sodium tripolyphosphate is often used as an admixture to ensure the water retention of concrete , Fluidity and cohesion, inhibit the slump loss of concrete mixture over time.
Everyone who has worked in the project knows that the concrete mixture is composed of cement, coarse and fine aggregates, water, admixtures and mineral admixtures. The main function of industrial grade sodium tripolyphosphate in concrete construction is to maintain the fluidity of the concrete. In the case of basically unchanged, the water consumption of concrete can be reduced, thereby improving the strength and durability of concrete, or under the same cement dosage and water-cement ratio, the fluidity of concrete can be increased, and the workability of concrete can be improved.
First of all, what are the factors that affect the slump of the concrete mixture?
(1) Cement
(2) Mineral admixture
(3) Aggregate
(4) The amount of additives
(5) The influence of environment on concrete slump
(6) Dynamic control during transportation
(7) Adjustment of mix ratio
Concrete workability, specifically to ensure the normal progress of construction, the mechanism of industrial sodium tripolyphosphate admixture: through the following three aspects, the flocculation structure is disintegrated.
1. The surface electrical properties of cement particles repel each other
2. Solvated film increases sliding ability
3. Increased dispersion, increased fluidity and strength
The main function of sodium tripolyphosphate is to directly form a stable complex with Ca2+ ions, instead of forming "insoluble" calcium phosphate with Ca2+ protons after hydrolysis. In the initial stage of cement hydration, sodium tripolyphosphate hinders the formation of the hydration product Aft, inhibits the crystal growth of the hydration product CH, and delays the hydration of C3S and C3A.
With the increase of the sodium tripolyphosphate content, the change of the slump loss over time of the concrete mixture becomes significantly smaller, indicating that the sodium tripolyphosphate has a good inhibitory effect on the slump loss rate of the concrete over time.
