A kind of 32.5 mixed Portland cement for rural township and anti-crack concrete and its preparation method

Abstract

The invention relates to the field of cement and concrete and discloses 32.5 mixed silicate cement for villages and towns and anti-cracking concrete and a preparation method thereof. The cement is prepared from, by mass, 40-65% of a silicate cement clinker, 10-25% of limestone, 3.0-6.0% of gypsum, 6-45% of a mixed material and 0.05-0.5% of a grinding aid; partial control parameters of the cement are as follows: the mass content of 3-32-um particles is higher than or equal to 70%, the mass content of SO3 is higher than or equal to 2.2% and lower than 3.5%, the pure slurry fluidity of a compatibility index of the cement and a water reducing agent is greater than or equal to 210 mm, and the loss rate in one hour is lower than or equal to 20%. The preparation process is simple, and the raw material sources are wide; when water, sand, stone and additives are added into the cement, C35-C20 grade concrete can be directly prepared without adding admixtures and is mainly used for common structural engineering of villages, towns and the like; the crack resistance grade reaches at least L-III, the compactness, homogeneity, durability and working performance of the concrete can be improved, engineering cracks are reduced, the concrete is economical, and the construction efficiency is also improved.

Description

technical field [0001] The invention relates to the fields of cement and concrete production technology and solid waste comprehensive utilization, in particular to a 32.5 mixed Portland cement for rural townships and crack-resistant concrete and a preparation method thereof. Background technique [0002] In 2018, the total production and consumption of cement in the country was 2.18 billion tons, of which, the production and sales of 32.5 grade cement were about 1 billion tons, accounting for about 45%-50%. Since the amount of cement clinker in C30 concrete with the largest usage is below 200kg / m3, and the total cementitious material (clinker, admixture) is about 400kg / m3, the cement clinker coefficient of ordinary concrete is below 0.5. In 2018, the output of ready-mixed concrete in Hunan was 96 million cubic meters, and concrete with C15-C35 strength grades accounted for more than 85% of all concrete. [0003] At present, about 50% of domestic cement is used for non-ready...

AI Technical Summary

Problems solved by technology

When 42.5 cement is used to prepare C15-C35 concrete, due to the large amount of admixture, and there is little or no sulfur trioxide in the admixture, only the introduction of sulfur trioxide into the cement will lead to gelation in the concrete Sulfate ions required for material hydration reaction are seriously insufficient or lacking, which seriously affects the performance of concrete

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