Study On Preparation And Properties Of Sulphoaluminate Cement Mortar

Since the advent of Portland cement,concrete has gradually become the main building material used in social development and has been widely used in various types of buildings.As a kind of low-cost,easy-to-manufacture and easy-to-use building materials,concrete can meet the requirements of most construction projects.Portland cement reinforced concrete structure is the most common structural form in today's architectural field.However,in some specific service environments,the Portland cement reinforced concrete structures show poor impermeability and poor erosion resistance.If these types of problems are not repaired or the protection is allowed to develop,it is very likely to cause reinforcement.Destruction of the safety of concrete structures is more evident in offshore engineering or coastal engineering.Research on repair materials of reinforced concrete materials has gradually become an important research direction.This paper studies the preparation and application of sulphoaluminate cement based repair mortar materials.The effect of repairing the components in the mortar on the physicochemical properties of the repair mortar was explored,and the sulphoaluminate cement-based repair mortar material that satisfies the requirements of the national standard was prepared,and its main durability performance was tested.On the other hand,two kinds of interfacial treatment agents used in repairing mortar engineering applications with different main constituents were prepared.The structural compactness improvement at the new and old interfaces of the repairing project was studied.At the same time,the interfacial treatment agent was used to repair mortar materials.The investigation of the impermeability and anti-erosion performance of the base material has been explored and the following results have been obtained:1.By comparing the effects of different kinds of retarder and water-reducing components in sulphoaluminate cement,boron acid and polycarboxylic acid were selected as retardation components for preparing sulphoaluminate cement-based mortar materials respectively.With the water reducing component,the optimum content of boric acid was0.14% and the optimum content of polycarboxylic acid was 1.0%.2.Comparing the effect of different dosages of latex powder on the fluidity and bond strength of repair mortar materials,the fluidity of repair mortar materials will decrease withthe increase of the amount of latex powder added,and the bond strength will be mixed with latex powder.The amount is positively correlated,and the comprehensive measurement of the two performance indicators determines that the best dosage of latex powder is 2%.3.Silicate cement clinker and gypsum were selected to be silicate modified components,which were added to sulphoaluminate cement repair mortar,and its influence on the physicochemical properties and durability of repair mortar was explored.Mortar strength will decrease with the addition of silicate modifying components.When the amount of silicate modified components is greater than 9%,the strength of the repair mortar material will be greatly reduced.% has little effect on the strength of the material and can significantly improve the impermeability,resistance to sulphate attack,resistance to chloride ion penetration,and resistance to carbonization of the repaired mortar material.4.Two types of interfacial treatment agents,silica sol and ethylene-vinyl acetate copolymer emulsions,and cellulose ether and styrene-acrylic emulsion,were prepared.It was found that both types of interface agents can significantly improve the adhesion of repair mortar materials.The strength of the junction,the interfacial treatment agent with cellulose ether and styrene-acrylic emulsion as the main body has high drying bonding strength,and is suitable for the repair engineering of dry service environment;the interface treatment agent mainly composed of silica sol and ethylene-vinyl acetate copolymer emulsion is water resistant Good performance,strong penetration into the surface layer of the base material,suitable for offshore repair works,selected as the interface treatment agent for the prepared sulphoaluminate cement based repair mortar,and studied its impermeability and resistance to chlorine for mortar materials.Improved ion erosion performance.