Advanced Materials Research Vols. 250-253

Abstract: This paper presents an experimental investigation on the effect of incinerator bottom ash (IBA) fineness and the cooled process of molten IBA on fresh mortar properties and compressive strength of hardened mortars. IBA with two finenesses, an original IBA, and a pulverizing incinerator bottom ash (PIBA) powder, with maximum particle size of 4.75 and 0.074 mm respectively were used to partially replace sand and Portland cement at 0%, 10%, 20%, 30%, and 40% by weight. The pozzolanic activity characteristics of powder were obtained from melting the above PIBA in an electric-furnace at 1450 °C for 1 h. and chilled by quenching in water (WIBA) and air (AIBA). Results indicate that incinerator bottom ash caused a reduction in compressive strength, unit weight, and flowability values when used as a replacement for sand and cement. However, IBA can be processed by melting to regain reactive pozzolanic activity, which may be used to partially replace cement.

Abstract: In order to enhance the interfacial interactions between the sisal fiber (SF) and the polypropylene (PP) matrix, a water-solubility hyperdispersant which has amphipathic structure and flexible segment was used. Experimental results revealed that when the content of hyperdispersant is 5 percent, the impact strength of the composites was 27.4 kJ·m^-2 and the flexural strength of SF/PP composites was 40.1 MPa, which was 64 and 34 wt% higher than that of unmodified systems, respectively. Meanwhile, the crystallinity of the composites also leads to an increase.

Abstract: In order to make the new composite wall structure the group developed to adapt different regional natural conditions, and along with the demand of gradually in-depth study the damage characteristics of the new composite wall, need to research the mechanical properties of the wall filling materials. In this paper, the ZG-CSS Electronic Universal Testing Machine was used on the uniaxial compressive test of the three blocks(the mud billet block, the cotton stalk block, the recycled EPS lightweight concrete block), to analyze the failure characteristics of the blocks and the other mechanical properties, such as Poisson’s ratio, elastic modulus, then the full compressive stress-strain curves are given, and at last fitting the mathematical expression of the uniaxial compressive stress - strain curves. And this paper also gives the yield criterion based on the unified strength theory of the three ecological filling blocks.

Abstract: A new environment-friendly wall material- the unfired brick is produced by using clay, carbide slag, fly ash and cement as the main raw materials，and certain amount of chemical excitator. The primary mixing ratio is designed on the basis of its mechanical properties and durability. When adopting water curing under normal temperature and atmosphere pressure，the compressive strength，flexural strength and frost resistance of the unfired brick are measured. The results reveal that the optimum mixing ratio for unfired brick is: Carbide slag 30%，fly ash 30%，cement 25% and clay 15%. For the unfired brick formed by vibration with the optimum mixing ratio，the min. compressive strength of each brick is more than 10 MPa, the overall properties meet the requirement as specified in standard JC 239—2001“Fly Ash Brick”.

Abstract: The non-autoclaved aerated concrete block with greater than 7.5Mpa compressive strength is produced by using iron tailings, lime, aluminum powder, caustic alkali, water, cement and gypsum in the laboratory after the experimental study on the property of iron tailings produced by Anshan Iron and Steel Group. The optimal mix proportion is finally determined by adopting orthogonal experimental method, the evaluating indicator is compressive strength. Aerated concrete block that is made from iron tailing is trial produced according to the national standards, and then its strength is determined by sample examination.

Abstract: The aim of this study was to evaluate the influence of mix proportion parameters on anti-permeability of green high performance concrete (GHPC) and find out the main influencing factors. Applying grey relational analysis method, the relational grades between the influencing factors and diffusion coefficient of Cl^- of GHPC were calculated. Besides, the sequence result of influencing degree of the factors to affect the anti-permeability was obtained. The result shows that the importance of the factors affecting anti-permeability of GHPC has following sequence: water-binder ratio> sand ratio > dosage of cement> dosage of water reducing admixture > dosage of mineral fillers > dosage of fly ash. In order to improve anti-permeability of GHPC, water-binder ratio and sand ratio must be controlled strictly.

Abstract: Aiming at the high expense of high strength lightweight aggregate concrete (HSLWAC), low-cost HSLWAC was produced making use of the industrial wastes including fly-ash (FA) and ground granulated blast furnace slag (GGBS) as admixture, and the influences of these admixtures on the workability and mechanical properties of HSLWAC were studies. Result shows that HSLWAC whose cubic compressive strength is high to 70MPa at the age of 28d can be produced with mixing admixtures; the effect of mixing GGBS to the strength of HSLWAC is better than that of mixing FA; and mixing admixtures is useful for the improvement of the workability of HSLWAC; However, the brittleness of HSLWAC rises with the increase of its strength.

Abstract: To utilize the recycled powder as concrete additives, self-compaceing concerte with recycled powder, granulated blast-furnace slag and granulated limestone were tested for slump-flow, compressive strength, modulus of elasticity and drying shrinkage. Reduction in superplasticizing effect of high-range water reducer was found for concrete with recycled powder. Compressive strength of concrete with recycled powder were the same as those with granulated limestone, and lower than those with granulated blast-furnace slag. Concrete with recycled powder showed lower elastic modulus and higher drying shrinkage than those with granulated blast-furnace slag and granulated limestone. The addition of granulated blast-furnace slag together with recycled powder to self-compacting concrete improved superplasticizing effect of high-range water reducer and properties of concrete.

Abstract: Eco-cement produced from waste concrete was proved to be feasible in early research. The seed crystal of ground granulated blast furnace slag (GGBS) was utilized in this research to lower the sintering temperature of eco-cement clinker. The mineral compositions of clinker with GGBS seed crystal was analyzed by X-ray diffraction (XRD), and the mechanical properties of eco-cement with GGBS seed crystal was also tested. Four main cement minerals were all observed in eco-cement clinker and the compressive strength of the eco-cement pastes can approach to about 66 MPa at 28 curing days. The results showed that GGBS seed crystal was favourable for the formation of cement minerals at a lower temperature. It can help reduce by about 50~100°C for the sintering process of cement clinker. Content of GGBS seed crystal should better be in the rage of 5%~8%, and the suitable sintering temperature should be 1350°C.

Abstract: Ethylene - vinyl acetate copolymer (EVA)-modified mortar is widely used in China because of better adhesion strength and flexibility as compared to traditional one. This paper, based on a laboratory program, evaluated the effects of EVA-cement and different fillers on interface properties of EVA-modified cement mortar such as adhesive strength and dynamic cracking resistance, and the mechanism was also analyzed by scanning electron microscopy (SEM). The results showed that under laboratory condition, adhesion strength and dynamic cracking resistance of EVA-modified cement mortar increased with EVA-cement rising. Interface performance of the EVA-modified mortar improved greatly as EVA-cement increased from 0% to 12% and amplification slowed down when it increased further. EVA-cement around 12% was the optimal proportion considering all factors in this study. Fillers of different particle grade contributed to interface properties of EVA-modified cement mortar, A/fillers around 1/6~2/3 is the optimal proportion in this study.