Research And Engineering Application Of Heavy Concrete

It has been a difficult problem for the engineers to solve the anti-floating andweight balancing of underground structures in the coastal areas. In recent years heavyconcrete has been widely used for its advantages as low-cost, eco-friendly andeasy-construction.With a combination of experimental study and theoretical analysis, a systematicstudy of the raw materials and their properties, mix design and performance of theheavy concrete was conducted in order for a safe and reliable application in bottomslabs of structures or components.Results of the study indicate:1, It is preferable to use high-density and low-costcement with low heat of hydration. Coarse and fine aggregate should be the samematerial with similar density to ensure the homogeneity of the concrete.2, Water consumption, aggregate gradation and air content of concrete affect theapparent density of the weight-balancing concrete if density of aggregate is fixed. Theapparent density of the concrete increases linearly with the increase of aggregate’sapparent density; the density of the concrete decreases with the increase of wateradded. Two particle size grading is preferable and the optimum ratio is3:7. Thedensity and apparent density of the concrete are both maximized under suchconditions.3, Mix proportion design was determined with a combination of qualityproportion and volume proportion. The concrete mixed with this method can be usedfor the construction directly.4, A complete construction plan needs to be made to ensure the construction ofheavy concrete with the consideration of its characteristics like high apparent density,easy segregation, etc.5, Steel slags can be used to the production of the concrete if the desired densityof the concrete is less than3000kg/m3. The use of steel slags in the concrete not onlycan meet the requirement of construction but also can conform to national standardsregarding energy saving and environmental protection. The use of steel slags hasrelative low-cost comparing with other heavy materials and has significant social andeconomic benefits. Content of free calcium oxide is required to be less than3%.6, Lots of engineering applications of the concrete like Beijing People’sLiberation Army302Hospital and around railway projects in the Northeast indicate that the mix proportion, engineering performance requirements and design methodproposed in this study are feasible, applicable and reliable, which builds a solidfoundation for the further use of the concrete in a wider area.