The pullout testing of geosynthetics is essential for studying interface interaction in the soil-reinforcement system. In this paper, a new method for testing interface properties of geotextiles is proposed. The inter...The pullout testing of geosynthetics is essential for studying interface interaction in the soil-reinforcement system. In this paper, a new method for testing interface properties of geotextiles is proposed. The interface frictional characters of two kinds of geotextiles (woven and needle-punched nonwoven) are investigated through pullout test. Nonwoven specimen has more wide variety of displacement along length than that of woven under the same pressure because of their different extensibility. The greater the elongation and deformation of specimens, the more evident the variations of displacement along reinforcement from front to pullout end. The greater the normal pressure, the smaller the displacement of every position along length with the same pullout load. The study focuses on the effects of the tensile modulus and the difference of pullout response between woven and nonwoven geotextiles.展开更多
The particle size distribution of rockfill is studied by using granular mechanics, mesomechanics and probability statistics to reveal the relationship of the distribution of particle size to that of the potential ener...The particle size distribution of rockfill is studied by using granular mechanics, mesomechanics and probability statistics to reveal the relationship of the distribution of particle size to that of the potential energy intensity before fragmentation, which finds out that the potential energy density has a linear relation to the logarithm of particle size and deduces that the distribution of the logarithm of particle size conforms to normal distribution because the distribution of the potential energy density does so. Based on this finding and by including the energy principle of rock fragmentation, the logarithm distribution model of particle size is formulated, which uncovers the natural characteristics of particle sizes on statistical distribution. Exploring the properties of the average value, the expectation, and the unbiased variance of particle size indicates that the expectation does notequal to the average value, but increases with increasing particle size and its ununiformity, and is always larger than the average value, and the unbiased variance increases as the ununiformity and geometric average value increase. A case study proves that the simulated results by the proposed logarithm distribution model accord with the actual data. It is concluded that the logarithm distribution model and Kuz-Ram model can be used to forecast the particle-size distribution of inartificial rockfill while for blasted rockfill, Kuz-Ram model is an option, and in combined application of the two models, it is necessary to do field tests to adjust some parameters of the model.展开更多
To address the need for producing a cheap,single-component,hot-applied compound joint sealant with high quality for sealing joints and cracks in concrete and flexible pavements without using primer for installation,a ...To address the need for producing a cheap,single-component,hot-applied compound joint sealant with high quality for sealing joints and cracks in concrete and flexible pavements without using primer for installation,a hot-applied modified asphalt sealant was produced by blending up about 30% starch into 20% citric acid.The starch and the asphalt cement were mixed at a temperature of above 160 ℃.Thus the waterproofing asphalt was manufactured to protect the surface of various shapes and types from water leakage using the citric acid.Results indicate that this sealant complies with the requirements of ASTM D-1191,D-6690-06a and D-7116-05.The citric acid is a kind of reliable materials for asphalt cement,which can be widely used in paving and waterproofing construction materials,and this offers profound engineering and economic advantages.展开更多
This article deals with the results of the research on the behaviors of the rural buildings made up of local materials during earthquakes. This article reveals the mechanical properties of masonry detected based on ex...This article deals with the results of the research on the behaviors of the rural buildings made up of local materials during earthquakes. This article reveals the mechanical properties of masonry detected based on experimental research results on wall samples made of local materials such as mud bricks, clay and straw mixture, rubble stones and limestones cut in standard sizes. In addition, the constructive measures prepared for the earthquake resistance of rural structures and the application techniques of these buildings in common construction are also generalized in this article.展开更多
In order to improve the efficiency of EPS integral thermal insulation building design and optimize the construction process of insulation construction, this paper uses experiment parts and simulation form to design th...In order to improve the efficiency of EPS integral thermal insulation building design and optimize the construction process of insulation construction, this paper uses experiment parts and simulation form to design the thermal insulation construction process, and evaluates the effect of heat preservation. Based on the finite element theory this paper designs adding process of insulation material EPS in the thermal insulation layer, and establishes the radiation heat conduction model of EPS material, finally obtains the solid heat conduction equation. Finally this paper uses ANSYS software to do simulation on the strength and temperature of EPS construction, and evaluates the quality of construction works, which provides technical reference for the design of integrated thermal insulation buildings.展开更多
1920s and 1930s architecture has often been associated with the use of modern materials, such as reinforced concrete, glass and steel, mainly thanks to the role given them by the historiography of the modern, of prese...1920s and 1930s architecture has often been associated with the use of modern materials, such as reinforced concrete, glass and steel, mainly thanks to the role given them by the historiography of the modern, of presenting a break with former tradition and of spreading the need of architectural renewal. The study of architecture from the point of view of construction techniques evidences, instead, how architectural renewal started earlier, during the 19 century and involved the whole realm of building, even tradition-associated materials, such as wood and stone. Indeed, artificial stone (which appeared in early 19 century) represents--above all in France--a link between traditional construction in stone and the newborn reinforced-concrete technique, so as to underline the gradual shift from 19 century construction codes to the new industrial construction techniques, which in the 1920s and 1930s tend to overlap and blend, in this way determining a material continuity of modern and 19 century architecture.展开更多
文摘The pullout testing of geosynthetics is essential for studying interface interaction in the soil-reinforcement system. In this paper, a new method for testing interface properties of geotextiles is proposed. The interface frictional characters of two kinds of geotextiles (woven and needle-punched nonwoven) are investigated through pullout test. Nonwoven specimen has more wide variety of displacement along length than that of woven under the same pressure because of their different extensibility. The greater the elongation and deformation of specimens, the more evident the variations of displacement along reinforcement from front to pullout end. The greater the normal pressure, the smaller the displacement of every position along length with the same pullout load. The study focuses on the effects of the tensile modulus and the difference of pullout response between woven and nonwoven geotextiles.
基金Chongqing Science and Technology Committee on basic research(No.2001-74-29) and Ministry of communications on Western Communications Construct Research Item(No. 200231800034)
文摘The particle size distribution of rockfill is studied by using granular mechanics, mesomechanics and probability statistics to reveal the relationship of the distribution of particle size to that of the potential energy intensity before fragmentation, which finds out that the potential energy density has a linear relation to the logarithm of particle size and deduces that the distribution of the logarithm of particle size conforms to normal distribution because the distribution of the potential energy density does so. Based on this finding and by including the energy principle of rock fragmentation, the logarithm distribution model of particle size is formulated, which uncovers the natural characteristics of particle sizes on statistical distribution. Exploring the properties of the average value, the expectation, and the unbiased variance of particle size indicates that the expectation does notequal to the average value, but increases with increasing particle size and its ununiformity, and is always larger than the average value, and the unbiased variance increases as the ununiformity and geometric average value increase. A case study proves that the simulated results by the proposed logarithm distribution model accord with the actual data. It is concluded that the logarithm distribution model and Kuz-Ram model can be used to forecast the particle-size distribution of inartificial rockfill while for blasted rockfill, Kuz-Ram model is an option, and in combined application of the two models, it is necessary to do field tests to adjust some parameters of the model.
文摘To address the need for producing a cheap,single-component,hot-applied compound joint sealant with high quality for sealing joints and cracks in concrete and flexible pavements without using primer for installation,a hot-applied modified asphalt sealant was produced by blending up about 30% starch into 20% citric acid.The starch and the asphalt cement were mixed at a temperature of above 160 ℃.Thus the waterproofing asphalt was manufactured to protect the surface of various shapes and types from water leakage using the citric acid.Results indicate that this sealant complies with the requirements of ASTM D-1191,D-6690-06a and D-7116-05.The citric acid is a kind of reliable materials for asphalt cement,which can be widely used in paving and waterproofing construction materials,and this offers profound engineering and economic advantages.
文摘This article deals with the results of the research on the behaviors of the rural buildings made up of local materials during earthquakes. This article reveals the mechanical properties of masonry detected based on experimental research results on wall samples made of local materials such as mud bricks, clay and straw mixture, rubble stones and limestones cut in standard sizes. In addition, the constructive measures prepared for the earthquake resistance of rural structures and the application techniques of these buildings in common construction are also generalized in this article.
文摘In order to improve the efficiency of EPS integral thermal insulation building design and optimize the construction process of insulation construction, this paper uses experiment parts and simulation form to design the thermal insulation construction process, and evaluates the effect of heat preservation. Based on the finite element theory this paper designs adding process of insulation material EPS in the thermal insulation layer, and establishes the radiation heat conduction model of EPS material, finally obtains the solid heat conduction equation. Finally this paper uses ANSYS software to do simulation on the strength and temperature of EPS construction, and evaluates the quality of construction works, which provides technical reference for the design of integrated thermal insulation buildings.
文摘1920s and 1930s architecture has often been associated with the use of modern materials, such as reinforced concrete, glass and steel, mainly thanks to the role given them by the historiography of the modern, of presenting a break with former tradition and of spreading the need of architectural renewal. The study of architecture from the point of view of construction techniques evidences, instead, how architectural renewal started earlier, during the 19 century and involved the whole realm of building, even tradition-associated materials, such as wood and stone. Indeed, artificial stone (which appeared in early 19 century) represents--above all in France--a link between traditional construction in stone and the newborn reinforced-concrete technique, so as to underline the gradual shift from 19 century construction codes to the new industrial construction techniques, which in the 1920s and 1930s tend to overlap and blend, in this way determining a material continuity of modern and 19 century architecture.