Applied Mechanics and Materials Vols. 584-586

Abstract: This paper is aimed at demonstrating the possibilities of adaptingQuantile Regression Neural Network (QRNN) to estimate the distribution ofcompressive strength of high performance concrete (HPC). The databasecontaining 1030 compressive strength data were used to evaluate QRNN. Each dataincludes the amounts of cement, blast furnace slag, fly ash, water,superplasticizer, coarse aggregate, fine aggregate (in kilograms per cubicmeter), the age, and the compressive strength. This study led to the followingconclusions: (1) The Quantile Regression Neural Networks can buildaccurate quantile models and estimate the distribution of compressive strengthof HPC. (2) The various distributions of prediction of compressive strength of HPCshow that the variance of the error is inconstant across observations, whichimply that the prediction is heteroscedastic. (3) The logarithmic normaldistribution may be more appropriate than normal distribution to fit thedistribution of compressive strength of HPC. Since engineers should not assumethat the variance of the error of prediction of compressive strength isconstant, the ability of estimating the distribution of compressive strength ofHPC is an important advantage of QRNN.

Abstract: Due to the demand of the architectural features and production processes, so that the structure can’t be constructed according to specification requirements to set corresponding expansion joints. This leads to the structure to form a super-long concrete structure. Such structures have large force and deformation under the action of temperature, and even cause cracking of the structure, which seriously impacts on the safe and proper use of structure. Further, if the structure is longer than the specification maximum spacing of joints, just relying on the qualitative construction measures to deal with the impact of the temperature effect on the structure can’t meet the requirements of structural design. Meanwhile, now the quantitative calculation of temperature effect isn’t unified at home and abroad，the adverse effect of the structural temperature effect is an urgent problem. In this paper, regarded the actual electrolytic aluminum plant long concrete structure as the research object, and used finite element analysis program to study the quantitative analysis to explore the laws of temperature stress and deformation size of the long concrete structure. It provides a reference for the construction and seamless design of future similar structure.

Abstract: Barnacle is a major creature in marine fouling organisms, it increases static load and dynamic load of marine structures. In this paper, the change of stress on marine concrete surface covered with barnacles is studied. Moreover, a simplified model is established. The result shows that the stress of seawater increases by 0.53 times on the concrete surface, which is covered with barnacles.

Abstract: This paper studied the influence of preparation method and electrode on properties of carbon fiber electrically conductive concrete by testing flexural strength and electrical resistance. Carbon fiber electrically conductive concrete is prepared by using dry mix method and wet mix method, the electrodes of which are stainless steel mesh and stainless steel sheet. The results show that the wet mix method of carbon fiber electrically conductive concrete is better than the dry mix method. The stainless steel sheet used as electrode in electrically conductive concrete is better than the stainless steel mesh. The long-term electrical resistivity of carbon fiber electrically conductive concrete is a constant value.

Abstract: This paper mainly presents the study of preparation and application of green vegetation concrete, pervious concrete, and aquatic conservation concrete. The research includes material screening, mix proportion, operating points, construction process, and application scope. It has been observed that green and eco-friendly concrete can protect urban ecological system from departure of balance and contribute to realizing the sustainable development.

Abstract: The behavior of the bearing capacity of the reinforced concrete columns confined with basalt fiber reinforced plastic sheet (BFRP) under axial compression is analyzed by the finite element method, and obtain the ultimate compressive strength and stress distribution of the BFRP. The analysis results show that the simulation results agree well with the experimental results, the strength and ductility of the BFRP reinforced concrete columns are improved obviously. The ratio of the strength test values and simulation values is between 0.91~1.14, the error is within an acceptable range. Then based on the strength of FRP confined concrete columns model, the test values are compared with those of the strength model calculation values, the ratio of the simulation values and calculated values is ​​between 0.94 to 1.03,that means the simulation values are credible. The mechanical properties of the BFRP reinforced concrete column are improved significantly.

Abstract: This paper describes the basic properties of decoration materials such as texture, color, texture, shape and other construction materials, focuses on the analysis of its use in decoration, protection, space partition, emphasis its selection and use on particular attribute space, emotion ,regional and environmental protection , the combination with the character of architectural features and the harmony of artistic styles.Based on this, the designer can make a space design which can meet customer demand through the depth understanding of the various properties of the materials.

Abstract: A tension-compression cycle fatigue test was performed in order to study the fatigue property of C50 concrete with pre-cracks in cyclic loading. The stress ratio was-1 and the amplitude was 0.2 MPa ~1.30 MPa. The results show that the modified coefficient of fatigue strength is 0.198~0.265 and the infinite life fatigue strength is below 0.45MPa. While the log value of fatigue life is approximately linear with the amplitude of fatigue load stress, the discreteness of fatigue life, the particularity of concrete, has little to do with the amplitude. The S-N, P-N fatigue life curves and the constant fatigue life diagram of pre-crack concrete are obtained.

Abstract: Hot recycled asphalt mixtures are used more widely in road construction and reconstruction at present. The recycle of asphalts can reuse the waste asphalts and bring economic benefits. Meanwhile it can protect the environment and save the energy. The mix design is an important step for regeneration of the old asphalts. And it is critical to the performance of hot recycled asphalt mixtures. This paper illustrates the mechanism of hot recycling of asphalts and proposes a simple and useful method of mix design for hot recycled asphalt mixtures. In the process, the performances and grading of reclaimed materials were evaluated. And the composition of raw materials with different contents were tested for selection of the best mix. The results show that the method is feasible by practise.

Abstract: Foam-based WMA are the most commonly used techniques. Gansu Department of Transportation recently let its first foaming warm mix asphalt in RAP project in response to need to evaluate the foaming warm mix asphalt technology in RAP and how it correlates with material specific to Gansu Province. Three foaming warm mixtures with RAP were designed. Based on this, Marshall volume indicators and pavement performance were tested and contrasted for three foaming warm mixtures with RAP and corresponding HMA. Foaming warm mixtures with RAP were produced at 130°C-140°C which is lower 10°C-20°C. The result show that 15% to 30% RAP can be added into foaming warm mixtures. Foaming warm mix asphalt technology can reduce 20°C of compaction temperatures compared with HMA. And its pavement performance can meet regulatory requirements.