To enhance the serviceability of steel bridge deck pavement(SBDP)in high-temperature and rainy regions,a concept of rigid bottom and flexible top was summarized using engineering practices,which led to the proposal of...To enhance the serviceability of steel bridge deck pavement(SBDP)in high-temperature and rainy regions,a concept of rigid bottom and flexible top was summarized using engineering practices,which led to the proposal of a three-layer ultra-high-performance pavement(UHPP).The high-temperature rutting resistance and wet-weather skid resistance of UHPP were evaluated through composite structure tests.The internal temperature distribution within the pavement under typical high-temperature conditions was analyzed using a temperature field model.Additionally,a temperature-stress coupling model was employed to investigate the key load positions and stress response characteristics of the UHPP.The results indicate that compared with the traditional guss asphalt+stone mastic asphalt structure,the dynamic stability of the UHPP composite structure can be improved by up to 20.4%.Even under cyclic loading,UHPP still exhibits superior surface skid resistance compared to two traditional SBDPs.The thickness composition of UHPP significantly impacts its rutting resistance and skid resistance.UHPP exhibits relatively low tensile stress but higher shear stress levels,with the highest shear stress occurring between the UHPP and the steel plate.This suggests that the potential risk of damage for UHPP primarily lies within the interlayer of the pavement.Based on engineering examples,introducing interlayer gravel and optimizing the amount of bonding layer are advised to ensure that UHPP possesses sufficient interlayer shear resistance.展开更多
Based on four-year field inspection and investigation on deck pavement of mastic asphalt on Jiangyin Bridge, cracking causes of mastic asphalt are studied. Cracks of deck pavement are summarized on crack length and wi...Based on four-year field inspection and investigation on deck pavement of mastic asphalt on Jiangyin Bridge, cracking causes of mastic asphalt are studied. Cracks of deck pavement are summarized on crack length and width to get a clear view of their propagations. Traffic surveys including traffic volume, axle load and vehicle speed were also conducted to assess their influences. Samples taken on-site were tested with pulling-out test and fatigue test to benchmark their properties. According to the inspection and tests results, it is concluded that the cracks are induced by rutting and fatigue. Lack of fatigue resistance, not well bonded to the steel deck and insufficient high temperature stability are supposed to be the main reasons as well as high density of low speed, excessively overloaded trucks.展开更多
To investigate the environmental impacts of steel deck pavement through the whole life cycle,the steel deck pavement was divided into five stages:raw materials production,asphalt mixture mixing,pavement construction,o...To investigate the environmental impacts of steel deck pavement through the whole life cycle,the steel deck pavement was divided into five stages:raw materials production,asphalt mixture mixing,pavement construction,operation management,and pavement removing stage.Based on the process-based life cycle assessment(PLCA)method,the calculation methods of energy consumption and gas emissions of two typical steel deck pavement systems(EA+EA pavement and GA+SMA pavement)were determined.The data lists of two pavements were analyzed,and the calculation model was built.Four characteristic indices including primary energy demand(PED),global warming potential(GWP),acidification potential(AP)and respiratory inorganics(RI)were used to quantify the environmental impacts of two pavements.The results show that the environmental impact of the GA+SMA pavement is more than 1.3 times that of the EA+EA pavement.Moreover,the critical stage of energy-saving and emission-reduction of EA+EA pavement and GA+SMA pavement are the raw material production stage and asphalt mixture mixing stage,respectively.展开更多
In order to study the influence of longitudinal slope on the mechanical response of steel deck pavement,a method of slope-modulus transformation was proposed for the mechanical analysis of the steel deck pavement base...In order to study the influence of longitudinal slope on the mechanical response of steel deck pavement,a method of slope-modulus transformation was proposed for the mechanical analysis of the steel deck pavement based on the time-temperature equivalence principle.Considering the mechanical action on a slope,a finite element model of the deck pavement was established to determine the critical load position of tensileand shear stress of the steel deck pavement.Additionally,the influence of longitudinal slope on the mechanical response of the deck pavement under the conditions of uniform speed and emergency braking was analyzed.The results indicate that the maximum transverse tensile stress at the pavement surface and the maximum transverse shear stress at the pavement bottom are always greater than their longitudinal counterparts under uniform speed.Under emergency braking,however,the critical slope gradient of t e maximum transverse and longitudinal tensile stress at t e pavement surface is 6%.The maximum longitudinal shear stess at t e pavement bottom is always greater ta n t e maximum tansverse shear stess.This stidy is helpful in t e strctural design of large longitudinal slope steel deck pavements.展开更多
Three beam samples of bridge deck pavement were prepared, with gradation types of AC-13, and AC-16 and combined AC-13＋AC-16. Four-point bending test was adopted to investigate the fatigue performance of these beam sa...Three beam samples of bridge deck pavement were prepared, with gradation types of AC-13, and AC-16 and combined AC-13＋AC-16. Four-point bending test was adopted to investigate the fatigue performance of these beam samples. The experimental results indicate that the initial bending stiffness is related to the type of beam sample samples decreases as the increase of the controlled strain fatigue resistance and bigger limiting bending strain at pared with single beam sample, the fatigue performance and testing temperature. Fatigue life of these level. The AC-13 beam sample exhibits better the given strain level and temperature. Corn- of combining beam samnle is relatively poor.展开更多
As an important part of steel bridge deck,the engineering quality and service condition of steel bridge deck pavement(SBDP)directly affects the capacity and operational efficiency of the bridge.This paper reviews the ...As an important part of steel bridge deck,the engineering quality and service condition of steel bridge deck pavement(SBDP)directly affects the capacity and operational efficiency of the bridge.This paper reviews the history of the development of SBDP in China over the past 20 years from the exploration stage,rapid development stage and prosperity stage.The development and application of SBDP at different stages are discussed in terms of materials,structure,design,performance evaluation,maintenance and rehabilitation,respectively.The advantages and disadvantages of different pavement materials and structures,and the application of different research methods are summarized.The review shows that the improvement of pavement materials and structures and the development of new materials should be further studied on the multi-scale to enhance the durability of pavement materials,so as to extend the service life of pavements.The design method of SBDP related to the synergistic effect of vehicle,pavement and bridge should be established,and the design concept and method standard of rigid base pavement structure should be improved and formulate a complete design standard.In addition,multi-disease intelligent identification system and equipment should be studied to track the entire course of disease development in real time.And it is necessary to develop appropriate algorithms to select and classify the complex data of disease and maintenance history.展开更多
The effect of multiple span suspension structure on the mechanical response of bridge deck pavement was studied, and finite element analysis (FEM) of stress and strain of pavement according to the bridge floor system ...The effect of multiple span suspension structure on the mechanical response of bridge deck pavement was studied, and finite element analysis (FEM) of stress and strain of pavement according to the bridge floor system features of super-long and high flexibility was made. Meanwhile, the FEM results were compared with those of the single span suspension structure. Three-stage analytic hierarchy process (AHP) is developed to analyze the mechanical response including whole bridge analysis, partial beams section analysis and orthotropic plate analysis. The most unfavorable load position was determined by the numerical solutions acquired from each stage to study the main mechanical index of multiple span suspension structure. The FEM results showed that the mechanical response numerical solutions by using the three-stage AHP are greater than those by simplified boundary condition, and the force condition of multiple span suspension structure is worse than that of the single span suspension structure.展开更多
Epoxy asphalt concrete has been one of the mainstream technology of steel deck pavement in China. But little specification about evaluation system for its distress condition has been researched and maintenance was sti...Epoxy asphalt concrete has been one of the mainstream technology of steel deck pavement in China. But little specification about evaluation system for its distress condition has been researched and maintenance was still unsystematic. The section weight coefficient of different distress is proposed by analyzing the applicability of the “Highway Performance Assessment Standards”. Indexes mainly including SDPCI PDR and PCR are presented to evaluate its distress condition. The evaluation system and maintenance plan decision tree were recommended which can assist scientific maintenance of epoxy asphalt steel deck pavement.展开更多
With the development of steel deck paving technology, the associated gussasphalt pavement system also develops maturely. In this paper, the structure characteristics and performance advantages are thoroughly explained...With the development of steel deck paving technology, the associated gussasphalt pavement system also develops maturely. In this paper, the structure characteristics and performance advantages are thoroughly explained by introducing the development course of gussasphalt. The material composition, properties and application effect of three typical pavement methods are analyzed. This paper is intended to give a relatively clear understanding regarding the specific features of gussasphalt, and provide some guidance to further expansion concerning gussasphalt pavement.展开更多
In order to improve the surface performace of epoxy asphalt pavement （EAP） for steel bridge deck, an epoxy asphalt chip seal （ ECS） covered by a cationic emulsified asphalt fog seal （i. e., fog-sealed chip seal）...In order to improve the surface performace of epoxy asphalt pavement （EAP） for steel bridge deck, an epoxy asphalt chip seal （ ECS） covered by a cationic emulsified asphalt fog seal （i. e., fog-sealed chip seal） isproposed and a laboratory study is conducted to design and evaluate te fog-sealed chip seal. First, the evaluation indices and methods of te chip seal on steel bridge deck pavement were proposed. Secondly, the worst pavement conditions during te maintenance time were simulated by te small traffic load simulation system MMLS3 and the short-term aging test for minimizing the failure probability of chip seal. Finally, the design parameters of fog-sealed chip seal were determined by the experimental analysis and the performance of the designed fog-sealed chip seal was evaluated in thelaboratory. Results indicate that the proposed simulation method of pavement conditions is effective and the maximal load repetitions on the EAPslab specimen are approximately 925 300 times. Moreover, the designed fog-sealedchip sealcan provide a dense surface with sufficient skid resistance,aggregate-asphalt aahesive performance and interlayer shearing resistance.展开更多
In order to analyze the dynamic response of pavement on long-span steel bridge decks under random dynamic loads, the irregularities of the pavement surface is simulated with the power spectrum density function, and th...In order to analyze the dynamic response of pavement on long-span steel bridge decks under random dynamic loads, the irregularities of the pavement surface is simulated with the power spectrum density function, and the random load is calculated according to a vehicle vibration equation of vehicle model. The mechanical responses of three different cases are compared by using a transient dynamic analysis method, i. e., under random dynamic load, constant moving load and dead load respectively. The results indicate that the mid-span of two adjacent transversal diaphragms is the worst load position. The maximum vertical displacement and the maximum transversal tensile stress of the pavement are 1.33 times and 1.39 times as much as those when only considering the impact coefficients. This study not only provides a theoretical basis for the mixture design and structural design of pavement, but also puts forward higher demand on the construction and maintenance for steel deck pavement.展开更多
This research investigated a pavement system on steel bridge decks that use epoxy resin(EP)bonded ultra-high performance concrete(UHPC).Through FEM analysis and static and dynamic bending fatigue tests of the composit...This research investigated a pavement system on steel bridge decks that use epoxy resin(EP)bonded ultra-high performance concrete(UHPC).Through FEM analysis and static and dynamic bending fatigue tests of the composite structure,the influences of the interface of the pavement layer,reinforcement,and different paving materials on the structural performance were compared and analyzed.The results show that the resin bonded UHPC pavement structure can reduce the weld strain in the steel plate by about 32%and the relative deflection between ribs by about 52%under standard axial load conditions compared to traditional pavements.The EP bonding layer can nearly double the drawing strength of the pavement interface from 1.3 MPa,and improve the bending resistance of the UHPC structure on steel bridge decks by about 50%;the bending resistance of reinforced UHPC structures is twice that of unreinforced UHPC structure,and the dynamic deflection of the UHPC pavement structure increases exponentially with increasing fatigue load.The fatigue life is about 1.2×10^(7) cycles under a fixed force of 9 kN and a dynamic deflection of 0.35 mm,which meets the requirements for fatigue performance of pavements on steel bridge decks under traffic conditions of large flow and heavy load.展开更多
The high temperature anti-rutting performance,water stability and low temperature bending property of epoxy asphalt mixture with 0%,15%,25%,40%,and 70% granulated and circular lightweight aggregates by weight are test...The high temperature anti-rutting performance,water stability and low temperature bending property of epoxy asphalt mixture with 0%,15%,25%,40%,and 70% granulated and circular lightweight aggregates by weight are tested,respectively.The dynamic responses under the vehicle load and in the opening process are analyzed to obtain the mechanical responses of pavements by using the finite element method.The complicated structure including a steel deck and a waterproof adhesive layer is made to verify the bond strength of the 2451-type epoxy asphalt binder.Research results show that the epoxy asphalt mixtures with lightweight aggregate replacement percentages from 0% to 70% all satisfy the requirements for steel bridge pavements.The epoxy asphalt mixture with a 70% circular lightweight aggregate replacement percentage is recommended because of its smaller density when compared with other epoxy asphalt mixtures.The shear stress increases with the increase in the opening angle and achieves its maximum at the maximum opening angle of 85°.Test results show that the Tianjin Bascule Bridge can be used for first opening after a 3 d pavement conditioning.展开更多
基金The National Natural Science Foundation of China(No.51878167)the Postgraduate Research and Practice Innovation Program of Jiangsu Province(No.KYCX23_0300).
文摘To enhance the serviceability of steel bridge deck pavement(SBDP)in high-temperature and rainy regions,a concept of rigid bottom and flexible top was summarized using engineering practices,which led to the proposal of a three-layer ultra-high-performance pavement(UHPP).The high-temperature rutting resistance and wet-weather skid resistance of UHPP were evaluated through composite structure tests.The internal temperature distribution within the pavement under typical high-temperature conditions was analyzed using a temperature field model.Additionally,a temperature-stress coupling model was employed to investigate the key load positions and stress response characteristics of the UHPP.The results indicate that compared with the traditional guss asphalt+stone mastic asphalt structure,the dynamic stability of the UHPP composite structure can be improved by up to 20.4%.Even under cyclic loading,UHPP still exhibits superior surface skid resistance compared to two traditional SBDPs.The thickness composition of UHPP significantly impacts its rutting resistance and skid resistance.UHPP exhibits relatively low tensile stress but higher shear stress levels,with the highest shear stress occurring between the UHPP and the steel plate.This suggests that the potential risk of damage for UHPP primarily lies within the interlayer of the pavement.Based on engineering examples,introducing interlayer gravel and optimizing the amount of bonding layer are advised to ensure that UHPP possesses sufficient interlayer shear resistance.
文摘Based on four-year field inspection and investigation on deck pavement of mastic asphalt on Jiangyin Bridge, cracking causes of mastic asphalt are studied. Cracks of deck pavement are summarized on crack length and width to get a clear view of their propagations. Traffic surveys including traffic volume, axle load and vehicle speed were also conducted to assess their influences. Samples taken on-site were tested with pulling-out test and fatigue test to benchmark their properties. According to the inspection and tests results, it is concluded that the cracks are induced by rutting and fatigue. Lack of fatigue resistance, not well bonded to the steel deck and insufficient high temperature stability are supposed to be the main reasons as well as high density of low speed, excessively overloaded trucks.
基金The National Key Research and Development Project of China(No.2018YFB1600304)the National Natural Science Foundation of China(No.51878167,51678146)the National Natural Science Foundation of Xizang,China(No.XZ2018ZRG-10)。
文摘To investigate the environmental impacts of steel deck pavement through the whole life cycle,the steel deck pavement was divided into five stages:raw materials production,asphalt mixture mixing,pavement construction,operation management,and pavement removing stage.Based on the process-based life cycle assessment(PLCA)method,the calculation methods of energy consumption and gas emissions of two typical steel deck pavement systems(EA+EA pavement and GA+SMA pavement)were determined.The data lists of two pavements were analyzed,and the calculation model was built.Four characteristic indices including primary energy demand(PED),global warming potential(GWP),acidification potential(AP)and respiratory inorganics(RI)were used to quantify the environmental impacts of two pavements.The results show that the environmental impact of the GA+SMA pavement is more than 1.3 times that of the EA+EA pavement.Moreover,the critical stage of energy-saving and emission-reduction of EA+EA pavement and GA+SMA pavement are the raw material production stage and asphalt mixture mixing stage,respectively.
基金The National Science Foundation of China(No.51778142)
文摘In order to study the influence of longitudinal slope on the mechanical response of steel deck pavement,a method of slope-modulus transformation was proposed for the mechanical analysis of the steel deck pavement based on the time-temperature equivalence principle.Considering the mechanical action on a slope,a finite element model of the deck pavement was established to determine the critical load position of tensileand shear stress of the steel deck pavement.Additionally,the influence of longitudinal slope on the mechanical response of the deck pavement under the conditions of uniform speed and emergency braking was analyzed.The results indicate that the maximum transverse tensile stress at the pavement surface and the maximum transverse shear stress at the pavement bottom are always greater than their longitudinal counterparts under uniform speed.Under emergency braking,however,the critical slope gradient of t e maximum transverse and longitudinal tensile stress at t e pavement surface is 6%.The maximum longitudinal shear stess at t e pavement bottom is always greater ta n t e maximum tansverse shear stess.This stidy is helpful in t e strctural design of large longitudinal slope steel deck pavements.
基金Funded by the National Natural Science Foundation of China (No. 50878171)
文摘Three beam samples of bridge deck pavement were prepared, with gradation types of AC-13, and AC-16 and combined AC-13＋AC-16. Four-point bending test was adopted to investigate the fatigue performance of these beam samples. The experimental results indicate that the initial bending stiffness is related to the type of beam sample samples decreases as the increase of the controlled strain fatigue resistance and bigger limiting bending strain at pared with single beam sample, the fatigue performance and testing temperature. Fatigue life of these level. The AC-13 beam sample exhibits better the given strain level and temperature. Corn- of combining beam samnle is relatively poor.
基金The authors appreciate the financial support from the National Natural Science Foundation of China(No.51878167)Qing Lan Project of Jiangsu Province。
文摘As an important part of steel bridge deck,the engineering quality and service condition of steel bridge deck pavement(SBDP)directly affects the capacity and operational efficiency of the bridge.This paper reviews the history of the development of SBDP in China over the past 20 years from the exploration stage,rapid development stage and prosperity stage.The development and application of SBDP at different stages are discussed in terms of materials,structure,design,performance evaluation,maintenance and rehabilitation,respectively.The advantages and disadvantages of different pavement materials and structures,and the application of different research methods are summarized.The review shows that the improvement of pavement materials and structures and the development of new materials should be further studied on the multi-scale to enhance the durability of pavement materials,so as to extend the service life of pavements.The design method of SBDP related to the synergistic effect of vehicle,pavement and bridge should be established,and the design concept and method standard of rigid base pavement structure should be improved and formulate a complete design standard.In addition,multi-disease intelligent identification system and equipment should be studied to track the entire course of disease development in real time.And it is necessary to develop appropriate algorithms to select and classify the complex data of disease and maintenance history.
基金National Science and Technology Support Program of China ( No. 2009BAG15B03)
文摘The effect of multiple span suspension structure on the mechanical response of bridge deck pavement was studied, and finite element analysis (FEM) of stress and strain of pavement according to the bridge floor system features of super-long and high flexibility was made. Meanwhile, the FEM results were compared with those of the single span suspension structure. Three-stage analytic hierarchy process (AHP) is developed to analyze the mechanical response including whole bridge analysis, partial beams section analysis and orthotropic plate analysis. The most unfavorable load position was determined by the numerical solutions acquired from each stage to study the main mechanical index of multiple span suspension structure. The FEM results showed that the mechanical response numerical solutions by using the three-stage AHP are greater than those by simplified boundary condition, and the force condition of multiple span suspension structure is worse than that of the single span suspension structure.
基金Sponsored by the Major Science and Technology Special Traffic and Transportation in Jiangsu Province(Grant No.2014Y02)the Jiangsu Natural Science Foundation(Grant Nos.BK20180113 and BK20181112)
文摘Epoxy asphalt concrete has been one of the mainstream technology of steel deck pavement in China. But little specification about evaluation system for its distress condition has been researched and maintenance was still unsystematic. The section weight coefficient of different distress is proposed by analyzing the applicability of the “Highway Performance Assessment Standards”. Indexes mainly including SDPCI PDR and PCR are presented to evaluate its distress condition. The evaluation system and maintenance plan decision tree were recommended which can assist scientific maintenance of epoxy asphalt steel deck pavement.
文摘With the development of steel deck paving technology, the associated gussasphalt pavement system also develops maturely. In this paper, the structure characteristics and performance advantages are thoroughly explained by introducing the development course of gussasphalt. The material composition, properties and application effect of three typical pavement methods are analyzed. This paper is intended to give a relatively clear understanding regarding the specific features of gussasphalt, and provide some guidance to further expansion concerning gussasphalt pavement.
基金The National Natural Science Foundation of China(No.51378122)
文摘In order to improve the surface performace of epoxy asphalt pavement （EAP） for steel bridge deck, an epoxy asphalt chip seal （ ECS） covered by a cationic emulsified asphalt fog seal （i. e., fog-sealed chip seal） isproposed and a laboratory study is conducted to design and evaluate te fog-sealed chip seal. First, the evaluation indices and methods of te chip seal on steel bridge deck pavement were proposed. Secondly, the worst pavement conditions during te maintenance time were simulated by te small traffic load simulation system MMLS3 and the short-term aging test for minimizing the failure probability of chip seal. Finally, the design parameters of fog-sealed chip seal were determined by the experimental analysis and the performance of the designed fog-sealed chip seal was evaluated in thelaboratory. Results indicate that the proposed simulation method of pavement conditions is effective and the maximal load repetitions on the EAPslab specimen are approximately 925 300 times. Moreover, the designed fog-sealedchip sealcan provide a dense surface with sufficient skid resistance,aggregate-asphalt aahesive performance and interlayer shearing resistance.
基金The National Natural Science Foundation of China(No.50578038)the Ph.D.Programs Foundation of Ministry of Education of China(No.20050286008)
文摘In order to analyze the dynamic response of pavement on long-span steel bridge decks under random dynamic loads, the irregularities of the pavement surface is simulated with the power spectrum density function, and the random load is calculated according to a vehicle vibration equation of vehicle model. The mechanical responses of three different cases are compared by using a transient dynamic analysis method, i. e., under random dynamic load, constant moving load and dead load respectively. The results indicate that the mid-span of two adjacent transversal diaphragms is the worst load position. The maximum vertical displacement and the maximum transversal tensile stress of the pavement are 1.33 times and 1.39 times as much as those when only considering the impact coefficients. This study not only provides a theoretical basis for the mixture design and structural design of pavement, but also puts forward higher demand on the construction and maintenance for steel deck pavement.
基金This work is jointly supported by the Natural Science Foundation of Jiangsu Province(Nos.BK20180113 and BK20181112)the Jiangsu Provincial Programme for High-Level Talents in Six Areas(No.XCL-CXTD-007)+1 种基金the Youth Programme of National Natural Science Foundation of China(Grant No.51908285)the Transformation Project of Scientific and Technological Achievements of Qinghai Province(No.2017-SF-134).
文摘This research investigated a pavement system on steel bridge decks that use epoxy resin(EP)bonded ultra-high performance concrete(UHPC).Through FEM analysis and static and dynamic bending fatigue tests of the composite structure,the influences of the interface of the pavement layer,reinforcement,and different paving materials on the structural performance were compared and analyzed.The results show that the resin bonded UHPC pavement structure can reduce the weld strain in the steel plate by about 32%and the relative deflection between ribs by about 52%under standard axial load conditions compared to traditional pavements.The EP bonding layer can nearly double the drawing strength of the pavement interface from 1.3 MPa,and improve the bending resistance of the UHPC structure on steel bridge decks by about 50%;the bending resistance of reinforced UHPC structures is twice that of unreinforced UHPC structure,and the dynamic deflection of the UHPC pavement structure increases exponentially with increasing fatigue load.The fatigue life is about 1.2×10^(7) cycles under a fixed force of 9 kN and a dynamic deflection of 0.35 mm,which meets the requirements for fatigue performance of pavements on steel bridge decks under traffic conditions of large flow and heavy load.
基金China Postdoctoral Science Foundation(No. 20110491342)Jiangsu Postdoctoral Science Foundation(No. 1101018C)the National Natural Science Foundation of China(No. 51178114,50908054)
文摘The high temperature anti-rutting performance,water stability and low temperature bending property of epoxy asphalt mixture with 0%,15%,25%,40%,and 70% granulated and circular lightweight aggregates by weight are tested,respectively.The dynamic responses under the vehicle load and in the opening process are analyzed to obtain the mechanical responses of pavements by using the finite element method.The complicated structure including a steel deck and a waterproof adhesive layer is made to verify the bond strength of the 2451-type epoxy asphalt binder.Research results show that the epoxy asphalt mixtures with lightweight aggregate replacement percentages from 0% to 70% all satisfy the requirements for steel bridge pavements.The epoxy asphalt mixture with a 70% circular lightweight aggregate replacement percentage is recommended because of its smaller density when compared with other epoxy asphalt mixtures.The shear stress increases with the increase in the opening angle and achieves its maximum at the maximum opening angle of 85°.Test results show that the Tianjin Bascule Bridge can be used for first opening after a 3 d pavement conditioning.
