| The energy crisis and environmental pollution in today’s society are the two outstandingproblems, burning of fossil fuels, resulted in these two increasingly serious problem, the useof concrete to absorb solar energy has great potential. For the the concrete collector ofresearch and development has become an important issue in developed countries, and made aseries of research results, but our concrete collector in its infancy.Ordinary cement concrete has good mechanical properties, but poor thermal properties,therefore, to carry out impact studies, master graphite, carbon black, iron oxide blackinfluence of mechanical and thermal properties of concrete composition on the mechanicaland thermal properties of concrete, research and development of solar heat-absorbing concretehas important theoretical and practical significance.Firstly graphite, carbon black, iron oxide black single doped cement mechanical andthermal properties were investigated using orthogonal design method, on this basis, graphite,carbon black, iron oxide black Admixed of cementmechanical and thermal propertiesinvestigated using SEM testing methods such as graphite, carbon black, and black iron oxidesingle blending of admixed the morphology of the cement hydration.By SEM analysis, thethree materials were added to the cement, the cement stone structure will lose, and introducedthe hollow crack. The mechanical properties of materials were further reduced and thethermal properties were further improved when were admixed added.Remixed mortarexperiments, silicon carbide partly replaced quartz sand and steel fiber reinforcedexperimental experiments were followed.The results of the actual solar endothermic experiment show that the actual endothermiceffect of the cement admixed better than single-doped, graphite, carbon black, iron oxideblack play their own material advantage, significantly improved with the collector effect.Therefore, in the mortar experiment, only select multiplexing （orthogonal） doped experiment.Standard fluidity was measured before the experiment and in the experiments under standardfluidity. The mechanical properties of the test materials must dry bulk density and thermalperformance, through the quadrature analysis, studies of graphite, carbon black, and blackiron oxide material performance parameters. The subsequent mortar experiments, studies showed that the maximum temperature than the the blank mortar sample temperature is7.82℃. By SEM analysis, we can see that graphite, carbon black, and black iron oxidecomplex doped cement stone morphology with greater impactation, the introduction of latticedefects such as holes crack more.On the experimental basis in the orthogonal mortar on the outside of the cement, chosethe optimal amount of graphite, carbon black, iron oxide black doped quality score. Furtherimprove the thermal properties of the material, explore different silicon carbide content oncomposite mechanical and thermal properties and analysis mechanism. The study showed that10%mass fraction of the silicon carbide total weight was optimal dosage. SEM analysisshowed that the cement paste and silicon carbide contact interface more closely than quartzsand, but adding too much silicon carbide will introduce more holes.Use dumbbell-shaped steel fiber to enhance the mechanical properties of the compositematerial, the results showed that the steel fibers significantly increase the compressive andflexural strength of the composite material, the thermal performance also improved.Hydration to28d, steel fiber volume content for the the4.5v%of the cement-based compositeflexural strength of9.37MPa compressive strength to48.91MPa. Oven dry bulk density is2302.6kg m-3, the thermal conductivity of8.3415W （m K）-1, the thermal diffusion coefficientof8.364810-6m2·s-1, volumetric heat capacity of142.35MJ （m3K）-1.The subject system to study the regularity and mechanism of concrete composition onthe properties of mechanical and thermal. The final preparation of the concrete collectormaterial construction requirements, good thermal properties. |
