Advanced Materials Research Vols. 168-170

Abstract: Previous studies have indicated that Chinese fir glulam has many defects on surface: color is singleness, knot is more, surface is roughness, etc. This paper presents a study on the manufacturing technology of sliced bamboo veneer-Chinese fir glulam composite panel. Sliced bamboo veneer were glued on both the top and bottom surface of Chinese fir glulam. The results showed: (1)sliced bamboo veneer can beautify the surface of Chinese fir glulam; (2)sliced bamboo veneer should directly overlay on the surface of Chinese fir glulam, and it is not suitable back lining non-woven fabric in gluing; (3)the optimal composite technological parameters are: unit pressure: 0.7MPa; hot pressing temperature: 100°C; hot pressing time: 4min.

Abstract: This paper proposes a concept of layered fiber reinforced concrete (LFRC) beam. In the concept of a LFRC beam, low-modulus fiber and high-modulus fiber are randomly dispersed and uniformly distributed into the concrete matries of the compression and tension zones, respectively. The static behaviors of LFRC beam are investigated from both experimental and numerical aspects. Four-point bending tests are performed on two simply supported T-shaped LFRC beam specimens and an ordinary T-shaped RC beam specimen with large scales. Comparison between the testing results of LFRC and RC beam specimens shows that the initial cracking load, flexural toughness and post-yielding stiffness of a LFRC beam can be significantly improved, but the ultimate loads are nearly without change. Numerical simulations are also carried out to investigate the static behaviors of the LFRC beam specimens. It is found that the simulation results are agreed well with that of tests. Further numerical parameter analysis for the LFRC beam specimens is conducted. The effects of high-modulus fiber volume fraction on the static behaviors of LFRC beams are studied. The research results show that the additions of high-modulus fibers have little effect on the initial stiffness, yielding loads and ultimate loads of LFRC beams; both the load and displacement at the initial cracking point increase linearly with the increasing volume fraction of the high-modulus fiber, but both the yielding displacement and ultimate displacement decrease linearly with the increasing volume fraction of the high-modulus fiber.

Abstract: In this paper, high-quality mineral admixtures and superplasticizer double mixing technology is used to produce high performance recycled concert (HPRC), and then steel fibers are used to modify the characteristics of HPRAC. The compressive strength, splitting tensile strength, ultimate bending load and fracture energy of HPRC with different content of steel fiber. Experiments suggest that with the increase of steel fiber content, the compressive strength doesn’t change too much, but the splitting tensile strength, ultimate bending load and facture energy increase dramatically. Therefore it can be concluded that increasing the content of steel fiber properly can improve the ductility and resistance to crack propagation of HPRC and enhance the ultimate load of HPRC bending member.

Abstract: Paulownia wood was drilled with some glass fibers fulfilled in the holes, which could be the core of the sandwich structures. In the manufacture processing, the fibers and resins left in the holes formed composite columns and merged with the facesheets. These could enhance the mechanical behavior of paulownia wood sandwich structures. Double cantilever beam(DCB) tests and bending analysis with finite element method were carried out. The improvement from the composite columns gave little contribution to bending behavior, but significant contribution to interfacial properties.

Abstract: Vinyl triethoxyl silicane, hydrogen silicone oil and microcrystal wax were separately used to modify the acrylic emulsion, wollastonite and synthesize the silicone wax emulsion for preparing exterior wall paint. The optimum conditions for the modifications and synthesis were experimentally presented. Under the optimum formula and operation conditions the silicone-modified acrylic emulsion exhibited good quality and all the property indexes of the exterior wall paint with a contact angle of about 140° were better than those regulated in the national standards issued by Chinese government. The structure of the modified acrylate emulsion, measured by infrared spectroscopy, was proved to be a real silicate-acrylate copolymerization emulsion.

Abstract: The purpose of this work is to modify the organosilicone-veova10-vinyl acetate (OSVVVA) copolymer emulsion with protective colloid in order to improve the viscosity of the original emulsion. The protective colloid was first prepared with polyacrylamide and polyethylene glycol as raw materials. The effects of use levels of protective colloid, vinyl triethoxyl silicane and potassium persulfate and reaction temperature on emulsion properties were investigated by orthogonal experiment and their optimum values were determined to be:50 g, 4 g, 0.5 g and 84 °C, respectively, under which the viscosity of the modified OSVVVA emulsion was greatly increased from 120 mPa•s to 430 mPa•s and the other properties of the modified OSVVVA were also satisfactory. The infrared spectra of the modified OSVVVA emulsion proved that the protective colloid was successfully grafted onto the OSVVVA copolymer emulsion.

Abstract: The exterior wall paint was prepared with silicone modified acrylate emulsion , silicone oil modified wollastonite and self-made emulsifying wax as main raw materials. The response surface experiment method was applied to investigate the effects of the three main raw materials on the contact angle of the finished coating. The results showed that the optimum ratio of pigment to base material, use level of silicone-acrylic emulsion and use level of emulsifying wax were separately 2.5, 20 g and 2.5 g under which the contact angle of the finished coating was 139.2 °and the coating exhibited good hydrophobic effect. The second multiple regression equation established by use of software of Design-expert 6.0 was in good agreement with the experimental results and can be applied to predict the contact angle under different level groups of the three main raw materials.

Abstract: The architectural heat-insulating coatings were prepared by means of high speed mechanical agitation when the polymer emulsions were used as binder of the coatings and the mixed nanoscale silicate composites and nano-oxides were used in the presences of some assistants. Two types of nanoscale silicate composites architectural heat-insulating coatings were designedly produced out. The wide-angle X-ray powder diffraction patterns and the SEM images of the products show that the coating films are dense. The thermal conductivities of the heat-insulating coatings are in the ranges of 0.094487~0.148973 W/m•°C which are obviously smaller than the standard rubber sheet, for example, the thermal conductivity of the calcium silicate nanowires composite coating is nearly 0.094487 W/m•°C only. The nanoscale silicate composite architectural heat-insulating coatings are in good agreement with the parameters in the GBT 17371-2008 (Silicate composite insulation coating).

Abstract: Fly-ash is an industrial waste burning pulverize coal boilers for thermal power plant and large enterprises, the steel slag is too a residue generated waste in steelmaking industrial processes, the average for every ton steel to produce half ton steel slag, steel slag and fly ash discharge amounts is very big, utilization ratio is very low. At present, a large number of steel slag is used of reclamation work, the remaining items is used rarely and large number is left storage. This paper is introduction steel slag and fly ash to do road base-course material, such can make good use of industry residue waste in large amount to reduce exploitation and cut down natural building stones, it is an application for ecological building materials again. Major study the steel slag and fly ash road features, these tests include materials compaction reality among them, mix design, unconfined compressive strength, split tensile strength, resilient modulus and other commonly used performance. Through comparative analysis, this two materials combination has good use of quality, it has greatly better than other materials such as lime-fly-ash stabilize crushed stone and lime-fly-ash soil and other materials. In particular, it has very good performance to reduce road base-course crack, the material has good resistance shrinkage and temperature shrinkage ability. Therefore, the combination of steel slag and fly ash can be done entirely road base-course and extend the road life.