| With the rapid development of my country’s economy and the scarcity of land resources,it is imperative to vigorously develop the ocean and build islands.The use of coral fragments on the islands and reefs to pour concrete can not only reduce costs,but also save resources on the land.At present,the research on coral concrete mainly focuses on mechanical properties,impermeability and resistance to chloride ion erosion.There are few studies on the long-term performance of coral concrete.Creep is an important time-varying characteristic,which has a bearing on the structure.Capability and durability have a big impact.Coral aggregates are light in texture,low in density,and high in water absorption,which makes the creep properties of coral concrete poured into it different from ordinary concrete.At the same time,as a new type of composite material,fiber has been widely used in various concretes.Therefore,this article aims to study the long-term performance of coral concrete and the effect of fiber on long-term performance.This paper takes coral concrete as the research object.The design strength of C30 is determined in the early stage,and basalt fibers of different dosages and lengths are mixed in it to determine the basic mechanical properties.On this basis,the performance of coral concrete is determined.The shrinkage performance and compression creep performance are measured.The results are as follows:The shrinkage deformation and compressive creep deformation of coral concrete are similar to those of ordinary concrete,showing a trend of rapid growth in the early stage and continuous slowdown in the later stage,and the two are relatively close in the early stage of the test,and the gap is gradually obvious in the middle and late stages.The shrinkage and creep of coral concrete are both equal.Larger than ordinary concrete.The incorporation of basalt fiber can inhibit concrete shrinkage and creep deformation.Among them,the fiber volume content is 0.04%,0.08%,and 0.12%,and 0.12% has the best suppression effect on both types of deformation.The volume content is the same.Among the fiber lengths of 6mm,12 mm,and 18 mm,the 18 mm fiber has the best inhibitory effect on both.In the creep process of concrete with a high load-bearing level,in addition to creep deformation,increasing damage is also produced.The damage development of coral concrete is similar to that of ordinary concrete,but the damage of the former is greater than that of the latter.The incorporation of basalt fiber can inhibit the development of coral concrete damage.When the volumetric content is 0.04%,0.08%,and 0.12%,the inhibitory effect increases with the increase of the content.When the fiber length is 6mm,12 mm,18mm,the improvement effect increases with the increase of the length.Comparing the measured creep data of coral concrete with the calculation data of several commonly used prediction models,a more suitable ACI209 model is selected,and on this basis,the correction coefficient is introduced to establish a creep prediction model suitable for coral concrete. |
