Experimental Study On Shrinkage And Creep Of All-coral Concrete

With the vigorous promotion of island engineering in China,coral concrete has been used more and more in practical engineering as a new type of concrete.The light and porous nature of the aggregate makes coral concrete different from ordinary concrete and conventional light aggregate concrete such as ceramsite and pumice concrete.The research status of coral concrete at home and abroad shows that the basic mechanical properties of coral concrete,bonding properties with reinforced materials and impermeability have obtained certain results,but there are few studies on long-term deformation performance.The deformation properties of coral concrete,such as shrinkage and creep,are affected by many factors,and there are large uncertainties.There are few studies on shrinkage and creep of coral concrete at home and abroad.Therefore,it is of great significance to study the long-term deformation performance of coral concrete.In view of this,this paper uses different water-cement ratio to prepare coral concrete,explores the characteristics of shrinkage and creep of coral concrete under different water-cement ratio and curing age,and provides theoretical basis for the analysis of coral concrete deformation performance and engineering application.The main contents and research results of this paper are as follows:(1)The basic mechanical properties of all-coral concrete with water-cement ratios of 0.37,0.4,0.47,and 0.58 were tested.The test found that with the increase of the water-cement ratio of the whole coral concrete,the compressive strength,elastic modulus and flexural resistance of the coral concrete The strength and thermal expansion coefficient showed a downward trend;the porosity test results of coral concrete showed that the porosity increased with the increase of the water-cement ratio of coral concrete.(2)The 180-year-old shrinkage deformation test of the whole coral concrete was carried out in an environmentally sealed laboratory.The characteristics,variation laws and mechanisms of the shrinkage-shrinkage age curve of coral concrete with different water-cement ratios were analyzed and compared with ordinary concrete.The test results show that as the water-cement ratio of coral concrete increases,the shrinkage deformation also increases accordingly.Compared with ordinary concrete,the early shrinkage rate of coral concrete is similar,but the final shrinkage value is larger than ordinary concrete.(3)Through the all-coral concrete compression and creep test,the effects of different water-cement ratio and curing age on the creep deformation of coral concrete were analyzed,compared with ordinary concrete,and the internal mechanism was explored.The test results show that the creep deformation of coral concrete specimens with large water ash is also large;the longer curing age can effectively slow down the development of creep deformation,which is beneficial to the long-term use of components;Influence,creep is slower in the early development,but the final value of creep is greater than ordinary concrete.