The Research On Mechanical Performance Of Structural Components Prepared With Magnesium Oxychloride Cement Concrete

Magnesium oxychloride(MOC) cement is mainly formed by magnesium chloride solution(MgCl2solution or MCS) and magnesium oxide(MgO) powder. After being cured in air, the articles are featured for their quick setting, lightweight, high strength, fire and corrosion resistance. MOC cement concrete is a composite material made up with MOC cement paste, sand, gravels, etc., usually perform higher strength than Portland cement concrete(PCC). Due to obvious disadvantages as low water resistance, poor volume stability and corrosion feature on rebars, MOC cement concrete is not popularized. But, theoretically, by admixing water-resisting admixture and other modifiers, MOC cement can take the place of PCC in structural components. Basing on the research on modification of Magnesium Oxychloride Cement(MOC, mainly on water-resisting and volume stability), aiming to establish new fields of MOC in materials in building structures, this paper presents the mechanical feature of MOC. Experiments were designed both on research of base material and structural components. In base material experiments, the feature of magnesium oxychloride cement (MOC) and its article is presented. Water-resistant admixture and other inorganic materials(silica fume, fly ash and slag)is added to the mix proportion to improve the mechanical properties of MOC concrete. By recording the uriaxial compression strength of concrete at7d-128d aging time, the influences on the early and late strength of MOC due to different inorganic materials and varied consumption of magnesium chloride solution(MCS) is analyzed. Using XRD(X-ray diffraction), SEM(scanning electron microscope) and EDS (energy dispersive spectrum) to investigate the micro-mechanism. In addition, the mechanical parameters(Young’s modulus, standard compressive strength, standard tensile strength, etc) were calculated basing on the results. In experiments of structural components, patterns were designed to test the bearing capacity and mechanical behavior. Theories of the Code for Design of Concrete Structures were used to predict the parameters of MOC concrete, and the bearing capacity was calculated and compared with the experimental results. Use the parameters obtainable and constitution relation given in the code, the finite element model was formed in ADINA. Comparison of all the results presented high consistency, which demonstrated the feasibility of predicting the mechanical properties with currently used code.