Experimental Study On Physical Properties Of Desalinated Sea Sand Mortar

With the rapid development of economy and society,the expansion trend of real estate construction industry is becoming more and more obvious.River sand,which is a traditional building sand,is being widely used in the fields of construction,roads,bridges,and decoration.However,with the increasing shortage of inland river resources,river sand mining is becoming more and more difficult.China has nearly 20,000 kilometers of coastline.The sea sand resources are inexhaustible.If we can effectively and reasonably make full use of sea sand resources,it will be a huge wealth for our society.For the soluble salts in the sea sand that have a corrosive effect on the steel bars in the concrete,this project adopted a fresh water flushing method to desalinate the salts(chlorine and sulfate ions)present in the sea sand to meet the national standards.This project also uses desalinated sea sand and other qualities to replace river sand to make desalinated sea sand mortar,and tests the working performance,physical and mechanical properties and durability of the mortar,and draws some basic measurement data and conclusions.This project carried out modification experiments on desalinated sea sand mortar,mixed fly ash in sea sand mortar and carried out various tests to obtain data and conclusions.The conclusions drawn from this topic are as follows:(1)With the increase of the replacement ratio of desalinated sea sand,the apparent density of the mortar tends to decrease,and the minimum apparent density is 2.045 × 103 kg / m3 when the replacement ratio reaches 100%.(2)With the increase of the replacement ratio of desalinated sea sand,the water absorption of the mortar is increasing.The maximum water absorption is 14.96% when the replacement ratio is 100%.(3)As the replacement ratio of desalination sea sand increased,the compressive and flexural strength of the mortar showed a decreasing trend.The curing age was 3d and the replacement ratio was 100%.The flexural strength of the test piece was 2.8367 Mpa.The strength is 10.959 Mpa.The longer the curing age of the mortar and the smaller the replacement ratio,the stronger the mortar’s ability to resist compression and bending.(4)As the replacement ratio of desalinated sea sand increases,the consistency of the mortar increases,the setting time decreases,and the fluidity decreases.When the replacement ratio is 100%,the consistency of the mortar is 65 mm,the setting time is 80 min,and the fluidity is 12 cm.(5)In terms of durability,replacing sea sand with sea sand will not improve the mortar’s anti-seepage ability and anti-freezing ability,but will reduce the mortar’s resistance to sulfate corrosion.(6)Modified sea sand mortar with pulverized coal will increase the apparent density of the mortar,increase the consistency and fluidity,set the time almost unchanged,reduce the water absorption,increase the flexural strength,and increase the later strength of the compressive strength.