Advanced Engineering Forum Vol. 5

Abstract: The use of styrene butadiene rubber (SBR) emulsions in concrete has been increasing in concrete construction and repair work due to its benefits to flexure strength, adhesion and impermeability. This research evaluated the influence of different contents (0%, 5%, 10%, 15%, and 20% by cement) of SBR on the mechanical properties and anti-permeability of the paste, mortar and concrete with the same water-to-cement ratio to analysis the SBR on the properties of them. For the mechanical properties, the compressive strength, flexure strength and elastic modulus were studied. The permeability was assessed by total charge-passed derived from rapid chloride permeability test (RCPT), all the samples were prepared and measured complying with the corresponding Chinese Industry Standard. Experimental results showed that the properties of the SBR modified concrete were associated with the corresponding properties of the SBR modified mortar and paste, and their properties changed in the same way with the incorporation of the SBR latex.

Abstract: In this paper, the influences of common admixtures including air entraining agent, superplasticizer, shrinkage-reducing agent, retarder, fly ash and slag on vibration viscosity coefficient of fresh concrete were analyzed. The results showed that the vibration viscosity coefficient of fresh concrete was markedly decreased when using UNF-5 naphthalene formaldehyde sulphonated superplasticizer. When SJ-2 air entraining agent, SZ103 shrinkage-reducing agent, retarder and slag were used, the vibration viscosity coefficient of fresh concrete was also reduced. But when fly ash was added, the vibration viscosity coefficient of fresh concrete was increased.

Abstract: The thesis utilizes the Penetrating Strength Detector of Shallow Pavement to conduct impacting penetration experiment, uniaxial compression test and diametral compression test to asphalt mixture of different void ratios and cycles of freezing and thawing, and then we’ve obtained the relationship between average penetration depth and compressive strength as well as tensile splitting strength of mixture, moreover, the initial reference standard of the Penetrating Strength Detector of Shallow Pavement is established. Afterwards, the thesis conducts impacting penetration test to the asphalt pavement cores from Chongzun freeway in Guizhou Province suffering from ice frozen damage. The effectiveness of the Penetrating Strength Detector of Shallow Pavement has been proved.

Abstract: Warm asphalt mixture develops rapidly throughout the world in recent years. Zeolite based warm mix is one of the warm mixtures. In this paper, seven kinds of zeolites including six natural zeolites and one synthetic zeolite are selected. As warm mix additives, their physical properties such as density, water content and pore arrangements are tested respectively. To evaluate the compacting properties of zeolites based warm asphalt mixture, AC-20 mixture is designed and compaction is conducted. It shows that zeolites can reduce the compacting temperature for both Marshall and gyratory compaction. Temperature is the main factors which influence the compaction effect. Type of zeolite affects compaction to some extent. Marshall compaction is more sensitive to zeolite than gyratory compaction.

Abstract: Based on the temperature field data collected from a self-developed pavement system, asphalt pavement temperature field distribution law in seasonally frozen regions was studied in detail. Test data illustrated that: The atmospheric and pavement temperature shows cycle sine rule; Minimum and maximum values of pavement temperature occur at surface, In winter, pavement temperature gradually increases with increasing depth, but has contrary result in summer; As the increase of depth, the fluctuation range of pavement temperature decreases gradually, which lead to the appearance of daily and annual constant temperature point; The max freezing depth appeared at 120cm and there will be freezing core in spring in seasonally frozen regions.

Abstract: In seasonally frozen regions, road construction often suffers from low strength,lack of durability, etc. Improving the typical clay’s workability in Changchun with lime and the Base-Seal stabilizer (BS-100) shows promising results. A comprehensive investigation to assess the soil characteristics influence is undertaken, so as the lime and liquid stabilizer (BS-100) content on the physical properties of stabilized soils in seasonally frozen regions. The optimum mix proportions, unconfined compressive strength, splitting strength, modulus of resilience, freeze-thaw action, water resistance and penetration-resistance were outlined. By comparing with current specifications, the Base-Seal stabilized soil as base material has higher early strength, higher after-strength and better frost stability.The results can be applied in road construction in seasonally frozen regions.

Abstract: Rut，referred to as a common damage of asphalt pavement ，is still a knotty problem to pavement researchers. Many reasons could cause rut, among which heavy duty, improper pavement structural combination design are two principal factors. As a result, three pavement structures and seven types of asphalt mixtures were used to evaluate the rutting resistance performance of different structural combinations. At first, through Marshall design method, the properties of asphalt mixtures were obtained such as gradation, asphalt content and so on. Based on the comparison of gradations and anti-rutting additives, the single layer rut was tested by wheel tracking test. Then, in order to consider influence of pavement structural design on pavement rut, six types of structure combinations under identical heavy duty condition were designed to perform rutting test. It shows that anti-rutting gradation and anti-rutting additives can improve rutting resistance performance of single layer. Also, a proper structural design could provide a better bearing capacity of wheel load even for heavy duty. It is better to integrate the anti-rutting gradation and anti-rutting additives into structural design. In this paper the results provide some new insight into the relationship between rutting resistance and mixture gradation, anti-rutting additives, heavy duty and structural combination. The consideration of these factors will give a better pavement design.

Abstract: In order to solve the rutting diseases of asphalt concrete pavement, latent heat materials for asphalt pavement were prepared and its controlling temperature performance was studied. Phase change materials (PCM), which were fitted to thermal environment of road were selected, phase change asphalt, diatomite powder and pottery sand granular composite phase change materials (CPCM) were prepared by three kinds of import modes. The CPCM were chosen by comparing the performance of above mentioned materials. Latent heat asphalt mixture (LHAM) was made by replacing mineral powder and fine aggregate with CPCM. Its controlling temperature ability was tested by temperature monitor system. The results show that, comparing to asphalt mixture, LHAM can reduce the temperature to 8-10°C. Therefore, the LHAM has a good effect on adjusting the road temperature.

Abstract: The alignment consistency of highways is an important guarantee for vehicle safety. In this thesis, by comparing the computing methods of ΔV85 and 85MSR, the author concludes that 85MSR is a more appropriate way to evaluate the highway alignment consistency. The author studies Ningfu section on Heda superhighway with 85MSR, pointing out the section with poor alignment consistency, and provides basic data for the analysis and prevention of this section and road improvement.

Abstract: It is more and more general of using industrial solid waste as the aggregates in construction materials for non-structural applications. But because of the developments and applications of reinforced blocks masonry structure in the modern masonry structure, especially in the mid-high and high storey buildings, there will be a growing interest of using industrial solid waste to produce high strength concrete small hollow blocks for structural applications. This experiment by mixing the different proportions of rock chips within the range of 30-70% as the replacement for sand prepared high strength concrete small hollow blocks which the compressive grade is MU 15.0, the influence of aggregates grading on the compressive strength of high strength concrete small hollow blocks was investigated at the same water/cement (w/c) ratio (0.45). In addition, the influence of the different curing methods on the compressive strength and shrinkage of high strength concrete small hollow blocks were also investigated, test results showed that high strength concrete small hollow blocks under the curing method which is the one-time pouring the ample amount of water, covered and sealed with plastic sheeting, the compressive strength had a better development, and the total shrinkage was larger than others.