Studies On Anti-mud Pumping Agent Based On Polycarboxylate Superplasticizer

As a new generation superplasticizer,Polycarboxylate superplasticizer has the advantages of low dosage,high water reduction and small drying shrinkage of prepared concrete,but it was sensitive to the clay content of gravel.When the clay content in the concrete is high,Polycarboxylate exhibits insufficient water reduction rate,large slump loss and other bad phenomena.This prevents the engineering application of polycarboxylate pumping agent.By systematic experimental research,we developed a type of anti-mud polycarboxylate pumping agent in this paper.That provide a technical supports for polycarboxylate superplasticizer with the problems of clay content in the concrete.By measuring the fluidity of cement paste and the workability,mechanical properties,carbonation resistance of concrete,we studied how added anti-mud components to reduce the impact of mud to polycarboxylate water reducer,and comparison with the same cost polycarboxylate pumping agent to verify the advantages of anti-mud polycarboxylate pumping agent,besides,by UV spectrophotometer and TOC analysis to research anit-mud component combat the effects of adsorption relationship between Polycarboxylate and mud.The main conclusions:(1)Added clay can reduce fluidity of cement paste,the use of anti-mud polycarboxylate pumping agent can increase initial fluidity of cement paste mixed polycarboxylate and reduce the loss of fluidity.(2)The increase in clay content can significantly reduce the fluidity of concrete,the anti-mud polycarboxylate pumping agent can improve slump retention ability of concrete mixed polycarboxylate,and does not affect thestrength of concrete.Clay stabilizer used alone or clay stabilizers and clay complexing agent compound used in anti-mud effect is remarkable.Both anti-clay polycarboxylatepumping agent has no effect on carbonation resistance of concrete.(3)The UV spectrophotometer used to study the adsorption behavior of polycarboxylate has some flaws.By TOC testing,we found clay stabilizer can reduce the adsorption of mud Polycarboxylate molecules.Clay stabilizers can be suppressed to reduce the adsorption of mud to the polycarboxylic acid molecule by reduce the volume expansion of mud.(4)The anti-mud Polycarboxylate pumping agent can significantly reduce the slump loss of concrete due to the amount of mud and reducing the sensitivity of the Polycarboxylate to mud,and it cost the same as polycarboxylate pumping agent.