Anti-freezing agent for cement concrete

Abstract

The invention discloses an anti-freezing agent for cement concrete. The anti-freezing agent is aluminosilicate solid powder which is obtained after palygorskite ore is subjected to modification treatment and is of a layer chain structure; the modification treatment comprises the following steps of (1), acidification: adding an acidifying solution into the palygorskite ore, agitating an obtained first mixture for 20 to 24 hours at 50 DEG C to 90 DEG C to carry out acidification treatment; (2), precipitant washing: after the acidification is terminated, stopping agitating, standing and precipitating reaction liquid for 1.5 to 2 hours, discharging upper water, and eluting a precipitant by using deionized water until eluting outlet water is colorless; (3), dispersion: adding the precipitant into an amount of water in which the precipitant is just soaked completely, adding a dispersing agent into an obtained second mixture under agitation, carrying out dispersion treatment on the precipitant for 5 to 7 hours at 35 DEG C to 60 DEG C, draining the superfluous water after the dispersion is completed, and collecting a solid; (4), drying and powder milling: drying the solid for 6 to 10 hours at 150 DEG C to 200 DEG C, and then milling the dried solid into powder. The anti-freezing agent provided by the invention has the advantages that early anti-freezing and long-time anti-freezing effects are good.

Description

technical field [0001] The invention belongs to the technical field of concrete, and in particular relates to a cement concrete antifreeze agent. Background technique [0002] Freeze damage is an important factor affecting the durability of concrete. For fresh concrete, the hydration reaction of cement must be guaranteed to proceed normally in order for the concrete to harden and gain strength. Water and temperature play a decisive role in whether the hydration reaction of cement can proceed normally. Winter construction is to ensure the hydration reaction of cement Can be completed normally and obtain corresponding strength. For the fully hardened concrete, the alternating high and low temperatures in winter and summer will cause the concrete to bear the freezing force, frost heaving force and the tensile stress caused by the shrinkage of the concrete slab itself. When these stress values ​​are greater than the ultimate stress of the concrete slab at low temperature , the...

AI Technical Summary

Problems solved by technology

The cost of inorganic salts is low, among which sodium chloride has a better antifreeze effect, but chloride ions will corrode steel bars and affect the quality of concrete; nitrites are carcinogenic and will return to alkali

Organic analogues are more costly than inorganic salts, but urea and amines with better antifreeze effects will release irritating gases and cause indoor VOCs to exceed the standard. If the alkali content in the antifreeze exceeds the standard, it will cause the alkali-aggregate reaction of the active aggregate and cause the concrete to expand. , cracked, causing an accident

[0005] Adding water reducer, early strength agent, antifreeze and air-entraining agent together as a concrete antifreeze type water reducer is suitable for the current commercial mixing process, but the combination of antifreeze and water reducer, early strength agent and air-entraining agent There is a certain inhibitory effect between them, and the compounded product cannot exert the effect of single component mixing

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