Advanced Materials Research Vols. 512-515

Abstract: Vibrating-type Asphalt Concrete is a new term. As a new type of asphalt concrete, various tests with regard to it are of practical significance. Mix of asphalt concrete indoors recommended by tests is verified and adjusted in the construction tests so that preparation, storage, mixing, transportation, paving, quality test, etc. of raw material of asphalt concrete and corresponding processing parameter can be identified to guide the construction of vibrating-type concrete core wall.

Abstract: The role of 3R (Reduce, Reuse, and Recycle) in constructing the Eco-society or Eco-city has been comprehensively recognized and promoted worldwide over the past two decades. Nowadays, several hot issues such as the energy saving, CO2 reduction, and eco-society have received great attention. Approximately 40% of global energy is used in the construction and subsequent operation stage, while a large amount of construction waste is produced during construction and after demolition. In Taiwan, the government continuously makes great efforts to promote the development of green building materials produced with the recycling construction waste over the past decades. However, the recycling green building materials are not extensively accepted and used in the construction industry of Taiwan. The objective of this study is to propose a strategy for promoting the recycling green building materials through the investigation of “cradle-to-cradle” life cycle of construction products. The key factors lowering people’s impression and purchase behavior have been studied. The disadvantage of existing policy of government is also discussed and compared. Finally, the present study attempts to propose a feasible strategy to assist government to promote the utility of recycling green building materials.

Abstract: The objective of this study is to evaluate pavement performance and dynamic mechanical properties of cold recycled mixtures consisted of modified asphalt emulsion-cement binder (CRMC). A cold recycled mixture design procedure that includes original material selection and gradation design has been applied. Then pavement performance of CRMC has been comparatively analyzed with the recycled mixtures without cement by theoretical and experimental methods. In addition, the tests for dynamic mechanical properties of CRMC have been conducted. The overall performance tests results indicate that CRMC has good strength, moisture stability, high temperature stability, low temperature stability, anti-shrinkage and fatigue resistance properties compared to the cold recycled mixtures without cement; Dynamic mechanical properties confirm that CRMC are similar to the hot mixtures asphalt (HMA), although a certain amount of cement is added.

Abstract: The aim of the research presented in this article was studying the basic physico-mechanical parameters of cement-bonded chip boards with hemp used as filler and by-products of energy production applied when modifying the bonding component. Determining and evaluating the basic parameters of boards of modified composition allowed for assessment of the effect of adding or substituting the bonding component within the cement chip board matrix. The work focused on the flexural strength, modulus of elasticity and density. In terms of anomalies in the cement matrix, i.e. uncommon crystalline phases in cement composites, representative samples were selected for differentially thermal and X-ray diffraction analysis.

Abstract: The influence of limestone powder, air-entraining agent and water binder ratio on chlorine ion (Cl-) penetration resistance of concretes was investigated by rapid Cl- penetration tests. The results show that the fineness of limestone powder is a key factor to Cl- penetration resistance of concrete. It can improve Cl- penetration resistance by introducing super fine limestone powder into concrete. Cl- penetration resistance of concrete increases as curing time increases. The concrete with lower water binder ratio has better Cl- penetration resistance. The introduction of air-entraining agent into concrete can enhance Cl- penetration resistance by improving micro pores structure. The optimum mixing amount is 0.3‰.

Abstract: The fatigue property of rectangular section beam for semi-flexible cold recycling mixtures has been analyzed basing on damage-fracture mechanics principles. Fatigue models of rectangular section beam have been put forward respectively, which includes both macroscopic cracks appearance and propagation process. Then parameters for fatigue models have been determined by the standard test for determining fatigue failure of compacted asphalt concrete subjected to repeated flexural bending. Finally, a fatigue life estimate formula of rectangular section beam is proposed by using mathematical decoupling method. Results indicate that the fatigue damage process play an important role in the whole fatigue process. Also, damage-fracture mechanics principles and methods are suitable for estimating the fatigue property of modified asphalt emulsion-cement cold recycling mixtures, which has a definite guiding purpose for projects.

Abstract: In this paper, the application status of existing building is discussed, the green transformation technology of existing building is presented, the selection method of green technology was discussed. At last, the suitability of green transformation technology for office building is analysis. The green transformation of existing office building must combine the characteristics of the green technology, according to climate characteristics and architectural features, to choice a suitable green technology.

Abstract: With worldwide production of fly ash approaching 800 million tonnes annually, increasing the amount of fly ash used in concrete will remove more material from the solid waste stream and reduce the amount ending up in landfills. However, most specifications limit the amount of cement replacement with fly ash to less than 25 or 30%. Concrete with fly ash replacement levels of at least 50% – referred to as high-volume fly ash (HVFA) concrete – offers a potential green solution. The following study investigated the structural performance of HVFA concrete compared to conventional portland-cement concrete. Specifically, the research examined both the bond strength of reinforcing steel in HVFA concrete as well as the shear behavior of HVFA reinforced concrete. The results indicate that HVFA concrete performs as well or better than conventional portland-cement concrete.

Abstract: The unburned brick was prepared by using the high titania blast furnace slag as an aggregate, styrene-acrylate emulsion as cementing materials and two admixtures. Factors such as amounts of admixtures and styrene-acrylate emulsion, forming pressure and curing time on the properties of the products were studied. The optimal process conditions for preparing the brick sample were as follows: mass fractions of the slag, styrene-acrylate emulsion, admixture 1, admixture 2 and water were respectively 70%, 8%, 8%, 10% and 4%, forming pressure 30 MPa, curing time 7 d. The properties of the brick sample prepared under these process conditions are better than that of MU 25 in GB / T 2542 - 2003.

Abstract: The major content in concrete is aggregates. Reduce its usage and replaced with recycled concrete aggregate (RCA) could not only mitigate consuming of natural resources but avoid the treatment of solid wastes. Furthermore, producing self-compacting concrete (SCC) with RCA is a way for traditional construction industry in saving energy and avoiding noise emission. To seek the proper way in preparation of SCC with RCA, preparation of RCA, composition design, microstructure evolution with hydration, and mechanical properties are investigated within this study. It is found that successful producing of SCC with RCA is not a complicated process.