Amino sulfonic acid water reducing agent with very low alkali content and its production process

Abstract

The amino sulfonic acid water reducing agent with very low alkali content is produced through: 1. mixing amino aryl sulfonating agent, phenol monomer and water, regulating the pH value of the reaction system to 7-9.5, dropping condensing agent and heating to 50-100 deg.c to react for 0.5-2 hr; 2. regulating the pH value of the reaction system to 8-11, adding compound containing amino radical and reaction at 70-100 deg.c for 2-10 hr; and 3. regulating the pH value of the reaction system to 8.5-13, reaction at 85-100 deg.c for 0.5-3 hr, lowering the temperature, discharging and spray drying. The material consists of amino aryl sulfonating agent 10.5-32 wt%, phenol monomer 3.2-16 wt%, compound containing amino radical 0-10.5 wt% and water 17.5-65 wt%. The present invention has the feature of low total alkali amount of 0-1.0 wt%.

Description

Technical field: [0001] The invention relates to an ultra-low-alkali sulfamate-based water reducer with a total alkali content of less than 1 percent and a manufacturing process thereof, which belongs to the technical field of building materials. Background technique: [0002] Alkali-Aggregate Reaction (AAR) is the reaction between cement, admixture, mixture and alkali (Na 2 O or K 2 O) It reacts with the active components in the aggregate, and gradually reacts several years after the concrete is poured (several years to twenty or thirty years). The reaction product absorbs water and expands to cause internal stress in the concrete, expands and cracks, and causes the concrete to lose its design performance. . Because the active aggregate is generally uniformly distributed after stirring. Therefore, once the alkali-aggregate reaction occurs, all parts of the concrete will generate expansion stress, and the concrete itself will swell and crack, and if it develops seriously,...

AI Technical Summary

Problems solved by technology

[0004] Since the alkali-aggregate reaction must have sufficient alkali content, sufficient amount of active aggregate and sufficient water supply in the concrete, the three conditions exist at the same time, and it is not required to limit the concrete in any case. However, it promotes the formation and development of shrinkage cracks in concrete and causes the deterioration of concrete structures and affects the durability of concrete. However, high alkali content is a greater threat to concrete.