Four fat and elongated(F&E)contents(0%,original,30%,and 40%)were investigated to evaluate the effects of F&Eparticles on the performance of porous asphalt mixture(P A).Laboratory tests including volumetric det...Four fat and elongated(F&E)contents(0%,original,30%,and 40%)were investigated to evaluate the effects of F&Eparticles on the performance of porous asphalt mixture(P A).Laboratory tests including volumetric determination,two-dimensional image analysis,Cantabro loss tests,breakdown tests,and permeability tests were conducted to evaluate the volumetric properties,the state of stone-onstone contact,durability,skeleton stability and permeability of PA,respectively.The test results indicate that the F&E content was a significant factor for total air voids,aggregate skeleton break down,and permeability.The functionality,rutting resistance,long-term durability,and skeleton stability decrease with the increase of F&E content since F&E aggregates in porous asphalt mixtures have a tendency to breakdown.Compared with traditional dense graded mixtures,PA is more sensitive to the F&E content due to an open graded aggregate structure.Therefore,the stricter requiement for F&E content should be met for porous asphalt mixtures than the one for traditional deese graded mixture.展开更多
The effects of the proportion of fine aggregate, the maximum size of the aggregate and the proportion of the 9.5 mm to 4.75 mm particle in the coarse aggregate on the properties of the porous concrete are investigated...The effects of the proportion of fine aggregate, the maximum size of the aggregate and the proportion of the 9.5 mm to 4.75 mm particle in the coarse aggregate on the properties of the porous concrete are investigated. Results indicate that the porous concrete with a cement dosage only 150 kg/m^3 has high strength and satisfying permeability when the aggregate has a passing percentage of 4.75 mm around 10% to 15%, with the increase of the maximum size of the aggregate, the strength of the porous concrete decreases and the permeability increases. When the proportion of the 9.5 mm to 4.75 mm particle in the coarse aggregate is about 20%, there are no interference among the particles by Weymouth theory, the strength of the pervious porous concrete reaches the peak value. The optimum continues gradation limit of the aggregate for porous concrete pervious road base material is recommended according to the theoretical calculation and experimental results.展开更多
Due to the relatively high density of conventional non-sintered lightweight aggregate(NLA),a low-density core-shell NLA(CNLA) was developed.Moreover,two types of porous lightweight aggregate concrete (PLAC) for wallbo...Due to the relatively high density of conventional non-sintered lightweight aggregate(NLA),a low-density core-shell NLA(CNLA) was developed.Moreover,two types of porous lightweight aggregate concrete (PLAC) for wallboard were designed,using both foam and lightweight aggregates.The effects of LA on lightweight concrete workability,compressive strength,dry shrinkage,and thermal conductivity were studied and compared.The bulk density of CNLA can be lowered to 500 kg/m^(3),and its cylinder crushing strength is 1.6 MPa.PLACs also have compressive strengths ranging from 7.8 to 11.8 MPa,as well as thermal conductivity coefficients ranging from 0.193 to 0.219 W/(m·K^(-1)).The CNLA bonds better to the paste matrix at the interface transition zone,and CNLA concrete has a superior pore structure than SLA concrete,resulting in a 20% improvement in fluidity,a 10% increase in strength,a 6% reduction in heat conductivity,and an 11% decrease in drying shrinkage.展开更多
基金Transportation Science and Technology Project of Jiangsu Province(No.7621000115)Science and Technology Project of Nanjing Committee of Housing and Urban-Rural Development(No.ks1611)
文摘Four fat and elongated(F&E)contents(0%,original,30%,and 40%)were investigated to evaluate the effects of F&Eparticles on the performance of porous asphalt mixture(P A).Laboratory tests including volumetric determination,two-dimensional image analysis,Cantabro loss tests,breakdown tests,and permeability tests were conducted to evaluate the volumetric properties,the state of stone-onstone contact,durability,skeleton stability and permeability of PA,respectively.The test results indicate that the F&E content was a significant factor for total air voids,aggregate skeleton break down,and permeability.The functionality,rutting resistance,long-term durability,and skeleton stability decrease with the increase of F&E content since F&E aggregates in porous asphalt mixtures have a tendency to breakdown.Compared with traditional dense graded mixtures,PA is more sensitive to the F&E content due to an open graded aggregate structure.Therefore,the stricter requiement for F&E content should be met for porous asphalt mixtures than the one for traditional deese graded mixture.
基金Funded by the Opening Fund of the Key Laboratory of Silicate Material Science and Engineering,Ministry of Education(No.YSJJ2004-13)
文摘The effects of the proportion of fine aggregate, the maximum size of the aggregate and the proportion of the 9.5 mm to 4.75 mm particle in the coarse aggregate on the properties of the porous concrete are investigated. Results indicate that the porous concrete with a cement dosage only 150 kg/m^3 has high strength and satisfying permeability when the aggregate has a passing percentage of 4.75 mm around 10% to 15%, with the increase of the maximum size of the aggregate, the strength of the porous concrete decreases and the permeability increases. When the proportion of the 9.5 mm to 4.75 mm particle in the coarse aggregate is about 20%, there are no interference among the particles by Weymouth theory, the strength of the pervious porous concrete reaches the peak value. The optimum continues gradation limit of the aggregate for porous concrete pervious road base material is recommended according to the theoretical calculation and experimental results.
基金Funded by the National Key R&D Programs of China (Nos. 2016YFC0701907, 2021YFB3802000 and 2021YFB3802004)。
文摘Due to the relatively high density of conventional non-sintered lightweight aggregate(NLA),a low-density core-shell NLA(CNLA) was developed.Moreover,two types of porous lightweight aggregate concrete (PLAC) for wallboard were designed,using both foam and lightweight aggregates.The effects of LA on lightweight concrete workability,compressive strength,dry shrinkage,and thermal conductivity were studied and compared.The bulk density of CNLA can be lowered to 500 kg/m^(3),and its cylinder crushing strength is 1.6 MPa.PLACs also have compressive strengths ranging from 7.8 to 11.8 MPa,as well as thermal conductivity coefficients ranging from 0.193 to 0.219 W/(m·K^(-1)).The CNLA bonds better to the paste matrix at the interface transition zone,and CNLA concrete has a superior pore structure than SLA concrete,resulting in a 20% improvement in fluidity,a 10% increase in strength,a 6% reduction in heat conductivity,and an 11% decrease in drying shrinkage.
