Advanced Materials Research Vols. 374-377

Abstract: In this article, based on a certain actual project, the main physical and mechanical performance including compressive strength, splitting strength, flexural strength and shear strength are studied in detail through the experiments. Different fiber types and volume ratio are chosen in the experiments for the purpose of determining the best quantities and types of steel fiber in concrete to lengthen the service life of deck pavements. It is showed that the research has some referential value for similar projects.

Abstract: Recycled concrete hollow blocks are made with recycled fine aggregates and recycled coarse aggregates, so recycled block is a kind of green environmental material and can be used for masonry structure. Shear property is one main mechanical property of recycled concrete hollow block masonry. From the shear test of masonry, the shear strength has been researched. At the same time the rule calculated results and test results are compared and analyzed, conclude the design value of shear strength in this paper. The test results show that recycled concrete block masonry has better shear strength, so it can be used for wall material.

Abstract: By using indirect tensile strength test and compression modulus test, the influences of variables, including recycled asphalt pavement (RAP) content and foamed bitumen content, on temperature susceptibility of mechanical properties of cold recycled mix with foamed bitumen (CRMFB) were studied. The results indicated that increase of RAP content had little impact on temperature susceptibility of CRMFB when small quantity of RAP (less than 70%) were contained, while enhanced temperature susceptibility of CRMFB was brought about when a large quantity of RAP (more than 70%) were contained. The mechanical properties, including strength and stiffness, manifested enhanced temperature susceptibility with the increase of foamed bitumen contents. Compared with HMA, CRMFB was obviously less susceptive to temperature.

Abstract: In order to improve the inherent fragility of alkali-activated fly ash-based geopolymer, the silica fume and styrene-acrylic emulsion were used to reinforce and toughen the geopolymer. The phase structure, morphology and chemical composition were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray fluorescence (XRF). The results showed that the mechanical properties of alkali-activated fly ash-based geopolymer were dramaticlly improved and the specimen with doping content of 10 wt% silica fume, 1wt% styrene-acrylic emulsion and 15wt% the alkaline excitation agent Na2SiO39H2O showed the highest compressive and flexural strengths of 42.11MPa and 5.30MPa in the ambient temperature curing 28d, respectively. SEM results indicated that doped silica fume and styrene-acrylic emulsion were embedded within the matrix of fly ash-based geopolymer. XRD results demonstrated that the mineral structures did not change obviously when silica fume and styrene-acrylic emulsion were added to the geopolymer

Abstract: Recycled concrete aggregate (RCA) and crushed clay bricks (CCB) have been increasingly researched and used in past two decades. However, studies focusing on the properties of dry-mortar with RCA and CCB are very limited. In this research, results from physical and mechanical properties of recycled mortar with fine recycled aggregate (FRA), fine recycled powder (FRP) and crushed clay brick (CCB) were secured. It is shown that sinking degree of FRA mortar can be adjusted in the range of 70-90mm and their water-maintainability is superior to natural sand mortar. However, compressive strength of FRA mortar at various ages decrease, compared to natural sand mortar under the condition of same mixed proportion. Compressive strength of FRA mortar is above 5.0MPa with mass ratio of aggregate to cement lower than 6.0.Workability of FRP and CCB mortar is similar to fly ash mortar and their apparent densities are under the 2.0g/cm³. Compressive strength of FRP and CCB mortar is near to 8.5 MPa at 28 days of age.

Abstract: Crush value index is a key parameter for measurement of coarse aggregate strength performance. In this paper the eight group of crush value index are tested for the recycled aggregate used of waste concrete which is gathered from three different remove construction plants. The experiment analysis result is shown that the crush value of recycled aggregate is greater 2.5 times than natural aggregate. Meanwhile, compared with air dried condition, the crush value index of saturated face dried condition is from 7.22% to18.2%. Furthermore the recycled aggregate can be suitable to make concrete requirement which compression strength grade is C35 and lower than C35 in China. In the experiment, comparative analysis is found that the RA-10 aggregate compressive strength is slightly from 2.06% to 8.7%. Those which are higher limit value of standard for test method of mechanical properties on ordinary concrete and the divergence are less than 10%. Consequently the recycled aggregate can be used for concrete, and its compressive strength is also fundamentally satisfied for requirement of concrete compressive strength.

Abstract: The demand for high performance concrete is increasing nowadays. The service life of high performance concrete has significant effect on the consumption of energy and resources. Adding good chemical and mineral admixtures to regulate and optimize the microstructure of concrete can ensure the service life of concrete structures and save great amount of cement simultaneously. It is a good way to turn waste into resource and turn the harmful into the beneficial.

Abstract: To determine the reaction degrees of Portland cement and fly ash in complex pastes, an experiment of hydration degree for composite pastes, hydrochloric acid dissolution method for fly ash and solution heat method for cement is applied. It is shown from the test that a rather precise result has been obtained by the combined method. The hydration degrees of cement and fly ash in composite pastes agree well with those from theoretical analysis.

Abstract: Shenzhen Stock Exchange (SSE) plaza, being constructed in Shenzhen of China, is a complex high-rise building with a raised podium above ground level. The podium extends outwards from the tower structure at a maximum cantilever span of 36 meters. The lifted podium is a new concept conceived by architects but a big challenge confronting structural engineers. In this paper, the structural systems, including tower lateral resisting system, podium supporting system, floor system and foundation, are introduced. In order to evaluate the structural performance under the action of three earthquake levels specified by Chinese code, three models using MIDAS, ETABS and ABAQUS have been built; the results from the three software presented. It has been shown that the performance targets of all three design earthquake levels can be attained

Abstract: This Article focus attention on the regional non-material cultural identity of the cities and towns around the the Yangtze River Delta . Historical and geographical context, rural festival temple fair, the daily living space is the three most representative components. It has great significance to the formation of regional economic, cultural and recreational attributes during the historical period Paper to the Xinchangtown of Nanhui County, take the historical maps of boiling down the wave; theannual festival, field activities, "March 28 Festival Temple Fair,"and traditional local cuisine as the main object of study: First, from thespirit of the idea, industry background and political and cultural backgroundand so, it analysis the impact of the history of formation and evolution of thesalt pan and the impact of salt industry for the spirit of the ancient localpeople, culture and life; Secondly, the elements of field culture arediscussed, then ,the festival market, business, entertainment space areanalyzed; Further attention later in the article section was taken to theinteraction of the field activities and the settlement pattern and itsmanifestations in daily life, which discusses the existence and impact of thelocal market place to the rural section and conduct the basic research for thethe rehabilitation of Festival Temple Fair