Research On The Proportion And Compressive Property Of High-strength Coral Reef Concrete

Coral reef is widely distributed in the South China Sea.The construction of coral reef plays an important role on the development of national marine economy.Making use of coral reef to mix concrete not only can effectively use the islands limited resources,but also reduce the cost if transporting building materials,shorten the time of construction.It is significant for the reef civilian and military construction..On the basis of research on coral concrete at home and abroad,this article studies the proportion of concrete,compressive strength,the mineral types of interfacial transition zone,the deformation characteristics of mixture of calcareous sand mortar and reef limestone.The results are as follows:(1)By studying the physical properties of calcareous sand and reef limestone,,this article makes the basic proportion of 50MPa coral concrete:cement 700kg/m3,ratio of water/cement 0.33,ratio of sand 50%,fly ash content 10%.(2)On the basis of orthogonal design,this article studies the compressive strength of the coral concrete,and analyses the result.It is concluded that the effects of cement content,sand ratio,water cement ratio and fly ash content on the cube compressive strength of coral concrete gradually decreases.Finally,according to the compressive strength,the optimum proportion of 50MPa coral concrete is:cement 700kg/m3,ratio of water/cement 0.33,ratio of sand 45%.(3)The article studies the effect of time on compressive strength of coral concrete.It points that coral concrete is early strength concrete.Its 7 days compressive strength can reach more than 85%of 28 days compressive strength.However,with the development of hydration,the strength growth slows down.(4)Depending on the X ray diffraction experiment of interfacial transition zone,it is found that magnesia has an important effect on the strength of interfacial transition zone.(5)Depending on the contrast of deformation characteristics of different types of cement mortar and mixture of cement mortar and reef limestone,it shows that compression modulus of calcareous sand cement mortar and reef limestone mixture,ordinary cement mortar and reef limestone mixture,calcareous sand cement mortar,ordinary cement mortar,reef limestone gradually increases.