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1.
YANG Xi wu 《保鲜与加工》2008,(4):136-140
To prevent asphalt pavement from cracking under low temperatures and prolong its fatigue life, we tested the properties of a new type of steel fiber asphalt pavement. The tests evaluated Marshall stability, dynamic ruts, and cleavage strength under both low and normal temperature conditions. We also analyzed the anti-corrosion property of steel fiber and the factors affecting the properties of the steel fiber asphalt mixture. The steel fiber asphalt pavement was installed on a highway in Chongqing, P. R. China to investigate the construction art of the steel fiber asphalt mixture and examine its effect in field use. The test results and concrete use in the field show that the cleavage strength and flexibility of steel fiber asphalt concrete increase due to the action of steel fiber. We conclude that the anti-cracking capacity of asphalt pavement under low temperature conditions can be improved by steel fiber. The construction art of steel fiber asphalt pavement is the same as common asphalt pavement without the necessity of anti-corrosion processing for steel fiber. The research results are useful for pavement material selection in low temperature regions and heavy traffic road pavement designs. 相似文献
2.
AH-70 road asphalt as the basis, Buton rock asphalt mixture pavement performance was studied by using six different Buton rock asphalt adding quality and six different AC20 aggregate gradation. The results show that Buton rock asphalt raw materials including the rock mineral significantly affects aggregate gradation and the pavement performance; reasonable choice OAC can significantly improve the road performance, and the road performance in the condition of 0.7%~1.3% optimum OAC is close to that of the SBS modified asphalt mixture, but Buton rock asphalt improving the water stability is limited; Buton rock asphalt optimum dosage is 23.7%, and Buton rock asphalt OAC and OAC of Buton rock asphalt raw material is almost the same. 相似文献
3.
Non homogenous settlement will occur while the expressway is constructed on soft ground. The differential settlement can cause the bigger additional stress inside the asphalt pavement structure accelerating bituminous pavement destruction. Therefore,we must choose reasonable pavement structure when constructing road on soft base in order to reduce the influence on surface layer structure from the differential settlement. Based on ABAQUS finite element method and through analysis, this article draws the conclusion that establishing unbound graded aggregate sandwich structure under the asphalt pavement structure can effectively reduce the horizontal additional stress of the stress controled layer and better prevent crack reflection which is beneficial for constructing the asphalt pavement structure on the soft ground. 相似文献
4.
Asphalt mixtures with high shear strength have great capability to resist perpetual deformation under high temperatures. We used a single penetration test to analyze the material design indexes for high performance asphalt mixtures. The test results show that the performance of the asphalt binder and the performance of the coarse aggregate, especially the fine aggregate, greatly affect the shear strength of asphalt mixtures. We also suggest that the coarse aggregate with a high aggregate particle index, fine aggregate with high angularity, and asphalt with high viscosity can increase sharply the shear strength of an asphalt mixture. Furthermore, the degree of compaction of an asphalt mixture should be controlled to guarantee excellent long term performance of asphalt pavement. 相似文献
5.
The rut resistance properties of large stone flexible bases are studied, taking into consideration heavy loads and using computer simulation and numerous indoor tests. In computer simulations of large stone flexible bases, a calculation method was formulated for predicting asphalt pavement rut under dynamic loads. The method was based on the coupling of vehicle dynamic loads and pavement surface unevenness. The results of indoor testing and three dimensional numeric calculation under dynamic loads are confirmed by tracking observation results of a test road. We conclude that the rut resistance properties of large stone flexible base asphalt pavement built using low grade asphalt and low crush value high performance aggregate with reasonable gradation is no worse than that of the semirigid base asphalt pavement, and that ruts mainly are caused by the lateral shear. 相似文献
6.
Based on the established cross-anisotropic layered elastic theory,the effect of inverted asphalt pavement structure by granular cross-anisotropy is analyzed.The result shows that,with the decrease of granular horizontal elastic modulus,the pavement surface deflection and tensile strain at bottom of AC are increased,but the tensile stress at bottom of semi-rigid base and compressive strain at top of subgrade are decreased.The thickness of AC has significant effect on the pavement surface deflection,tensile strain at bottom of AC and compressive strain at top of subgrade,while the granular cross-anisotropy has little effect on the critical inverted pavement responses for the thicker AC. 相似文献
7.
When paving SMA asphalt road surface, the temperature factor must be thought over which infects life-span of road surface. Winter and summer temperature distribution on a steel box girder bridge is simulated, compared with data measured on EGongYan Bridge in Chongqing and HaiCang Bridge in Xiamen. A change range of high road surface design temperature suit to China is given. 相似文献
8.
The effect of fiber in asphalt mixtures has attracted general concern. For study of this problem, four kinds of fibers are chosen in this test. Asphalt and modified asphalt are adopted in asphalt mixtures AC-16I. The road performance influenced by additional fiber was analyzed impersonally,i, e. the stability of asphalt concrete under high temperature condition, anti-crack ability under low temperature condition, the water resistance and fatigue performance. It was shown through the research that the optimum asphalt content, air void rate, clearance rate of the mineral powder, saturation degree, and the flow value were increased and the density was decreased after adding the fiber. The road performance, such as the stability of asphalt concrete under high temperature condition, anti-crack ability under low temperature condition, water resistance and fatigue performance, was obviously improved,and the high temperature stability and fatigue performance improved most evidently. The fiber asphalt mixture performance reached and even exceeded the modified asphalt mixture performance. The modified asphalt performance after adding fiber would be improved more greatly. 相似文献
9.
Firstly,the current development of the technologies for recycling of reclaimed asphalt pavement(RAP) in China and abroad is introduced in this study.The theoretic evidence is supplied for the feasibility and means of the recycling technology for RAP by analyzing the aged asphalt recycling mechanism.On the basis of it,a series of recycling processes for RAP are stated in detail,including the performance assessment of RAP,mix design and construction techniques of recycling asphalt mixture.The traits and actual example of different construction techniques for RAP supplied a good consultation for its reasonable choice.All of them would play a role in the research,application and spread of the recycling technologies for RAP in China. 相似文献
10.
Based on the Linear Elastic Multi-layer Theory, using the pavement finite-element program, this article discussed the shear stress distribution regularities and influencing factors in high grade asphalt pavement layers. The results demonstrate that the max shear stress appears in surface to 3cm depth span regardless of the material characteristic and thickness in each layer. The major influencing factors on the shear stress are modulus and Poisson ratio of asphalt layer, modulus of base layer. By comparing the database with testing results, to three asphalt layers pavement structure, it is necessary to check the shear strength in wearing layer and midlayer. When checking, the precious position must be found to calculate the max shear stress in each layer. 相似文献
11.
Experiments on the asphalt fume suppression agents and properties of asphalt concrete with fume suppression agent 
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下载免费PDF全文 Through lots of screening tests, two fume suppression agents, i.e. SBS and nanometer CaCO3, which can reduce the asphalt fume without affecting the properties of asphalt, are screened from seven additives. The best ratio of two agents for suppressing fume is presented by contrast tests of fume suppression effect, and the fume can be reduced about 30%. The properties of asphalt concrete with fume suppression agents and the mechanism of SBS and nanometer CaCO3 reducing the asphalt fume are investigated. The research findings are useful for reducing the asphalt fume in bad ventilation condition of channel pavement and urban road pavement construction. 相似文献
12.
A 33-hour field test of outdoor thermal environment was carried out in a typical teaching building cluster located in the hot and humid zone in summer. From the experiment results of local climate data, air temperature, humidity, wind velocity and wet bulb globe temperature (WBGT) at the pedestrian-level, and the typical ground surface temperature, the main characteristics of summer outdoor thermal environment of teaching building cluster in hot and humid zone are obtained. The results show that the patio, overhead and porous pavement can reduce the pedestrian air temperature and WBGT effectively at summer daytime. And the function of the following design methods to improve the outdoor thermal comfort at the summer daytime has the order like overhead>patio>porous pavement>imporous pavement>concrete road. The WBGT at all measuring points at nighttime are almost the same. The test results are further used to verify the existing mathematical models of outdoor velocity and WBGT. The results show that the relative errors are within 6%. Then, the calculation values are in good agreement with the experimental values. 相似文献
13.
The damage rate of asphalt pavement for the fatigue performance cracking is studied with axial loading by the relationshi Pof surface cueved index with Falling Weight Deflection basin, bottom pulling strain of asphalt surface and aumbers of axial loading. The predicting result of standard axial loading and more-classified loading is very different, so as its increasing rate with the time going. It fits real circumstance to predict the fatigue character of asphalt pavement according to more-classified loading and could be an effective measurement for predicting fatigue life of asphalt pavement ruder axial loading. 相似文献
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Asphalt mortar is an important component of gussasphalt mixture, a mixture of asphalt and mineral filler. Five filler-asphalt ratios are used. The high and low temperature performance changes of gussasphalt mortars with different filler-asphalt 相似文献
16.
In the study on the CRCP+AC composite pavement, the form and distribution pattern of cracks are two important factors influencing the performance and the lifetime of the pavement. The concrete damaged plasticity material model incorporated in the general purpose finite element software named ABAUQS was adopted to describe the mechanical characteristics of the CRC slab. Combining with the temperature field database drawn from the three-dimensional transient heat transfer analysis, the structural damage under the condition of temperature changing is analyzed. The structural damage evolution and the crack behavior of the CRC slab subjected to the thermal-mechanical coupling condition are further analyzed, which suggests that the role of the asphalt concrete surface is not confined only to the scope of improving the performance of the road, its capacity for improving the stress state of CRCP slab is worthwhile to be affirmed. And the reasonable thickness of AC layer should be designed in consideration of the thermal contraction and damage properties of the CRC slab comprehensively. 相似文献
17.
Based on the latest research, we introduce asphalt foaming principles and their characteristics and analyze the influencing factors from macro and micro perspectives. The methods of designing foamed bitumen mixture, the optimum mixing water content, the influence of curing conditions, laboratory testing methods, mechanical characteristics, and the influencing factors of foamed bitumen mixture are discussed. We outline some new asphalt foaming technologies used in warm mix asphalt. Viewpoints regarding the development of foamed bitumen are put forward by analyzing the design and the evaluation methods of foamed bitumen mixture, the development and the selection of asphalt foaming additive, the improvement of the manufacture techniques of foamed asphalt, and the technology of modified asphalt foaming. 相似文献
18.
To improve the performance of asphalt rubber mixture under high temperature, an optimal proposal was put forward which selected asphalt rubber mortar and aggregate gradation as the main objects. According to experimental tests, the anti rutting factors and phase angles of asphalt mortar was studied with different rations of filler bitumen. And then, with the characteristics of asphalt rubber, the optimal gradation was presented by means of the adjustment of aggregate gradation which chose dynamic stability and relative deformation as value indexes. The results shew that asphalt rubber mixtures would show an optimal high temperature performance if the following measures can be taken: (1) making an adjustment of ratio of filler bitumen to about 1.2; (2) replacing mineral powder with cement; (3) making an adjustment of aggregate gradation and lower the proportion of mineral powder based on SMA. 相似文献
19.
With the coming maintenance period of the aging road in China, the old asphalt pavement's recycling has become an important issue.By introducing the principle of the asphalt pavement recycling technology and the status quo of the application, this paper calls for a strengthened relational research and a heavy concern with the issues, so as to gain the optimum economical and social benefit. 相似文献
20.
It has been established that a pavement slab will curl up if a temperature gradient exists across the depth of a slab. A negative temperature gradient causes the slab edge to curl up while a positive temperature gradient curls up the slab center. Temperature stress in slabs is induced by self-weight and other slab constraints. At present in P. R. China, the total stress considered in cement concrete pavement design includes the load stress plus the temperature stress, and only transverse cracking from bottom to top is considered for concrete pavement. Slab responses under axial loads and temperature gradient coupling are not included. We modeled a single slab with a frictionless interface between the slab and foundation using the finite element method. Slab deflection and stress were calculated under axial loads at different slab positions and negative or positive temperature gradient coupling. The calculated results show that the different conditions of axial loads and temperature gradient coupling will change the maximum tension and cause various types of cracks in a slab. 相似文献