Preparation And Corrosion Resistance Of Magnesium Phosphate Cement New Energy Research

Magnesium phosphate cement(MPC)is a kind of new cementitious material which is made of MgO,phosphate and retarder.Compared with ordinary portland cement,MPC has the advantages of low temperature,high bonding strength,dry shrinkage,abrasion resistance and frost resistance.It is widely used in bridge,road and airport runway.So far,people of magnesium phosphate cement(MPC),the hydration mechanism,slow coagulation mechanism,microscopic structure,carbohydrate composition,setting time,mechanical properties,adhesion and repairing performance has made a lot of research work.But in the early stage of the experiment found that under hydroponic conditions and solution environment and the strength of magnesium phosphate cement will decline dramatically,which in a certain extent limits the its wide application.At present,the research on the corrosion resistance of magnesium phosphate cement is relatively small,so it has some practical significance to study the corrosion resistance of magnesium phosphate cement and its mechanism.In this paper the preparation of magnesium phosphate cement by reheating Magnesium Oxide,potassium dihydrogen phosphate,borax and fly ash.Using the orthogonal test method,the comparison and analysis of the magnesium phosphorus ratio(M/P),borax content and the amount of fly ash for factors of magnesium phosphate cement compressive strength of the paste impact were prepared.The 28d flexural strength reached 10.3MPa,28d compressive strength reached 47.38MPa,and setting time was 15min of magnesium phosphate cement.In the same time,the ordinary Portland cement,slag and phosphorus slag were used to prepare magnesium phosphate cement based composites,and the effect of Portland cement,slag and phosphorus slag on the properties of magnesium phosphate cement was studied.Magnesium phosphate cement has different degrees of shrinkage in the steam curing and water curing conditions.The content of fly ash can effectively improve the water resistance of magnesium phosphate cement,and the M/P value is generally between 4/1?5/1,which has good water resistance.The water resistance of the slag of magnesium phosphate cement composites was studied.The experimental results show that water conservation conditions of magnesium phosphate cement test block and the flexural compressive strength does have adverse effects,the anti bending strength with age increasing and slow the growth of,and the compressive strength of hydroponic conditions will occur in the inverted shrinkage phenomenon.The water resistance of magnesium phosphate cement can be improved with the addition of slag powder as an additive.Magnesium phosphate cement has good corrosion resistance in tap water,NaCl solution,Na2SO4 solution and MgCl2 solution.Magnesium phosphate cement has good resistance to Cl-and SO42+ corrosion by the test of magnesium phosphate cement.There is strength loss of magnesium phosphate cement in HCl solution and NaOH solution environment.NaOH solution was the most corrosion of magnesium phosphate cement.And through the micro analysis of magnesium phosphate cement by chemical erosion mechanism,the analysis found solution chemistry major failure of magnesium phosphate cement hydration formed struvite flocculent gel structure,so that the overall structure loose and porous,reduce the degree of compaction,and macro reflects poor resistance to chemical corrosion.