Applied Mechanics and Materials Vols. 357-360

Abstract: Compared with natural sand, manufactured-sand is of small porosity, poor grain shape and graded, which impacts mixes workability and the properties after hardening. In Concrete, playing the role of retaining moisture water is mainly powder, including cement, powder in the sand and fly ash etc. The amount of powder has a great influence on the properties of concrete, especially on its workability. This paper mainly discusses the influence of amount of cement, cementitious materials, fly ash, water-cement ratio and other factors on the workability, compressive strength and shrinkage of concrete. The experiments show that, in the case of the low amount of cement, workability of the manufactured-sand concrete mixture, compressive strength and shrinkage deformation of test block all meet the actual requirements.

Abstract: The sound absorption ability of screen or perforated membrane is studied based on rigid frame porous models combined with thin membrane resonance sound absorbing theory in this paper. Results show that the sound absorption of screen or perforated membrane is better considering the role of membrane than using the rigid frame porous models when the mass density of screen or perforated membrane is smaller. The rigid frame porous model is very accuracy to model the sound absorption ability of screen or perforated membrane when the mass density of membrane is greater. The parameter studies present that the sound absorption peaks move toward low frequency region with the increasing of the depth of air-back cavity, mass density and thickness of screens or perforated membrane and moves toward high frequency region with the increasing of the perforation and perforated radius of screens or perforated membrane when other parameters keep invariant.

Abstract: Recycled coarse aggregate solid concrete bricks were produced by QTY4-40 brick machine with strength grades of MU15-MU30. Compression and flexural strength of solid recycled coarse aggregate concrete brick were investigated. The impact of recycled aggregate on the solid concrete brick mechanical properties and physical properties was analyzed. The relationship between physical properties and strength, density was discussed.

Abstract: As the common waste of the production in daily life,a large number of stone powder, fly ash, coal gangue was abandoned, and it causes large tracts of land was occupyed and the environment was polluted. Therefore it is great singnificance to saving resources and protecting environment by studing the impact of the three kinds of wastes as mineral admixtures on the properties of concretetTest shows that when the replacement rate of the three kinds of admixture is 20%, the replace quanity is considerable and the basic requirements on compressive strength, the anti-permeability performance, frost resistance of the concrete can be satified;when the replace content of the stone powder or fly ash is 30%, the performance of the concrete decreases, it only can be applied in the engineering whose quality requirement is relatively low; the properties of the concrete can't meet the requirement of the engineering application when the the replacement rate of the coal gangue is 30%.

Abstract: After the 4-bromo-3,5-difluorophenyl acrylamide (BDPA) and acrylic acid were introduced into the epoxy acrylate (EA), the photosensitive epoxy acrylate (EFBDPA) with good performance was prepared through chemical graft modification. The structure of EFBDPA was confirmed by FTIR and ¹H-NMR. When the content of BDPA in EFBDPA was 20%, the cured coating of EFBDPA had better performance than the unmodified EA cured coating, its tensile strength, 80 % decomposition temperatures and the residual carbon ratio were improved 86%, 5.7 °C and 4.2 %, respectively.

Abstract: The paper studied the effects of different contents of beads on powder pressure entity dense packing density, mechanical performance of composite cement paste. The microstructure of the composite paste is researched by SEM analysis and nitrogen adsorption method. The results show that when the beads content is low, the compacting voidage decreases with the increased bead contents. When the beads content is 30%, composite cementing material achieves the densest packing density. The compacting voidage of composite cement powder has strong correlation with the pore structure and strength of hardened cement paste. When the compacting voidage value reaches minimum, the average pore radius and maximum pore radius of hardened cement paste reach the minimum values. In addition, the 28d strength of composite cement paste is higher than ordinary cement paste.

Abstract: The solidification method is a significant and resultful method for the disposal of dredged sediment. Solidified agents can be employed to improve the unconfined compressive strength (UCS) of sediment solidification. In this work, considering of economy and practicability, three kinds of optimized compound additives are selected and investigated on the effects of UCS of sediment solidification. 7d., 14d.and 28d. solidification stadium were taken to test the UCS of samples. Results showed that the activator had the best effect on increasing the UCS. The comparative tests also indicated that adding any kind of additive into the cement-based materials could improve the UCS of sediment solidification, the highest value of UCS was 11.02MPa (SCAHR). By means of scan electron microscope (SEM) technology, the microstructure images of the raw sample and solidified sample were obtained, which help to understand the development of UCS of the solidified sediments.

Abstract: In this study, the organic-inorganic composite elastic latex was prepared by using the polymerization process of pre-emulsification semi-continuous combined monomer dropping and investigated for the effect of the manner of the introduction of inorganic component and the amount of silica on the mechanical properties of the polymer film and water absorption. The results show that, when the sol is introduced with emulsion by the physical blending method and TEOS and A-151 are introduced together, the amount of them are respectively 1.5% and 9%, the organic-inorganic composite emulsion can be prepared. Meanwhile, if SiO₂ is added by the way of TEOS and A-151, the best film properties of organic-inorganic acrylate flexible latex will be obtained .

Abstract: Fired brick using hypocalcaemia fluidized bed boiler fly ash has been studied in this paper. It has been proposed that large amount of low calcium fluidized bed boiler ash fired brick has the best performance in the conditions of firing temperature of 1050 °C and holding time of eight hours. The influence of the amount of hypocalcaemia fluidized bed boiler fly ash to the performance of fired brick has been studied also. This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.

Abstract: Cellulose is one of the most abundant renewable resources on the earth and could meet the increasing demand for environmental protection property and biocompatibility of materials. In recent years, ionic liquid, as a new type of environmentally-friendly medium and soft functional material, has gained widespread concern, for it has provided broad space for the further development of cellulose chemistry. This paper selects 1 - propenyl-3 - methylimidazolium ionic liquid to dissolve and reproduce the cellulose, thereby preparing the gel-type wood-based composite. The reformed fiber bundles constitute an unclosed three-dimensional cross-linked network as the support frame which owns the microstructure similar to balsa wood as well as the stable chemical and physical properties. Its oven dry density is 0.221 g/cm³ and the porosity is over 87%. This kind of gel-type wood-based composite prepared by the green chemical processing could fix and store the carbon adsorbed by trees, which is conductive for the environmental protection.