Papers by Keyword: Cement-Based

Abstract: The effects of two admixtures content i.e. water reducer, cellulose ether and water-cement ratio on mechanical strength and dry density of cement-based lightweight thermal insulation board are studied. The result indicates that the water-cement ratio is the important influential factor, which is easier to get good workability. And based on the mechanical strength and dry density, the best range of water reducer content and cellulose ether content are 0.3%-0.6% and 0.4%-0.6% respectively.

Abstract: Using space electromagnetic wave propagation principle, environment requirements of building protective engineering structure and performance characteristics of cement-based composites, a design idea of cement-based composite with electromagnetic protection is presented in the present study. This design idea was tested and verified. According to the proposed new designed method, by optimizing and selecting the wave-transparent aggregate and absorbing agent material, the absorbing composite materials of cement-based electromagnetic protection, electromagnetic wave absorbent, energy saving and environmental protection can be improved. A new cement-based composite with electromagnetic protection and microwave absorbing properties (the minimum reflectivity is-8.4dB), wide frequency bandwidth, and letter mechanical properties was prepared by using a 20 mm sample between 8-18 GHz. The results provide a basis design and preparation of cement-based composite with electromagnetic protection.

Abstract: Concrete is the most widely used building material and due to its use, water tightness is one of the factors essential for many constructions. Materials applied on concrete surface as secondary protection can have various forms. One of the material group with waterproofing ability, are materials on so called "crystalline technology base". As this material is cement-based its wide world production brings significant effect on environment. To bring on building materials market new materials should be considered its environmental friendlier production. One of the ways for this group of materials with crystalline abilities is replacing cement by other substituent, at best by secondary raw material. This would bring double advantage, lowering usage of cement and on the other hand use of already produced secondary raw material. This article deals with new developed materials based on "crystalline technology" with cement partly replaced by fly-ash substituent. At this article are presented results of new developed screed and coating modifications and its effectiveness on concrete waterproofing.

Abstract: Cement mortar as the basic material and the fly ash and silicon fume as the research object, experiment and research were operated through adjusting the admixture replacing dosage and changing the mixture ratio of silica fume and fly ash. By testing the fluidity and strength and data analysis and discussion, some conclusions are drawn from the analysis, such as: fly ash makes the fluidity increasing with the admixture replacing dosage below 30%, and the fluidity declines with the mixture ratio of silica fume and fly ash increasing. 7d compressive strength decreases with the admixture replacing dosage increasing, 7d compressive strength increases slowly with the mix ratio of silica fume and fly ash. With the mix ratio of silica fume and fly ash increasing, 28d compressive strength of mortar also increases, and proper mix ratio of silica fume and fly ash is 1:1.

Abstract: This article describes test and results of long term effect by sulphate environment on new designed crystalline technology based material with fly-ash as partly cement substituent. At this article are presented results of new developed modification, which was the most effective and suitable for further commercial production during long term physical and mechanical tastings. Main aim of the experiment was to analyze ability of this new material to develop crystalline structure in capillary system and proof effectiveness of new developed crystalline structure in concrete pore system affected by long term sulfur medium attack.

Abstract: As a new environment-friendly waterproof material, polymer cement waterproof coating combines the rigidity of cement and the flexibility of polymer materials. The ratio of the L/P、the ratio of the C/P, the dosage of dispersant were discussed to investigate their effect on the coatings’ flexibility at low-temperature and the bond strength of wet surface.

Abstract: As a new environment-friendly waterproof material, polymer cement waterproof coating combines the rigidity of cement and the flexibility of polymer materials. The ratio of the liquid powder、the ratio of the C/P、the dosage of stuffing、the coating-forming additives、the defoamer were discussed to investigate their effect on the waterproof materials’ water resistance and water proofness.

Abstract: As a new environment-friendly waterproof material, polymer cement waterproof coating combines the rigidity of cement and the flexibility of polymer materials. The ratio of the liquid powder、the ratio of the C/P, the dosage of stuffing, the coating-forming additives, the defoamer were discussed to investigate their effect on the waterproof materials’ tensile performance and fracture elongation.

Abstract: Periodic and non-periodic 1-3 type cement based piezoelectric composites were fabricated by cut and filling technique, using P(MN)ZT ceramic as functional material and cement as matrix. The influences of periodicity of piezoelectric ceramic rods in the composites on electrical properties of all the composites were discussed. The results show that the non-periodic composites have larger dielectric factor and piezoelectric strain constant than those of the periodic composite. The impedance-frequency spectra analysis indicates that the non-periodic arrangement of ceramic rods can effectively restrict the lateral structural mode of the composite, accordingly reduces the coupling resonant between the thickness resonant mode and lateral resonant mode. The thickness electromechanical coupling coefficient of non-periodic composites is larger than that of the periodic composite. With increasing the non-periodic level of P(MN)ZT ceramic in the composites, the mechanical quality factor of the composites increases gradually. Therefore, 1-3 type cement based piezoelectric composites with different special abilities can be obtained by varying the periodic arrangement of P(MN)ZT ceramic rods in the composites.