Concrete Bridge Deck Pavement Research Articles

Design of Waterproof System for Cement Concrete Bridge Deck Pavement Based on Layer Functional Requirements

Design of Waterproof System for Cement Concrete Bridge Deck Pavement Based on Layer Functional Requirements

Analysis of alkali leaching mechanism on as-built cement concrete bridge deck pavement: View from the perspective of mesostructure characteristics

The emergence of a new distress mode, known as alkali leaching, has been increasingly reported in the cement concrete bridge deck pavement (CCBDP). The presence of defects in the pavement structure causes the accumulation and movement of alkaline solution. The examination of the internal pore features of deteriorated pavements is advantageous in order to comprehensively reveal the mechanism of alkali leaching on CCBDP. The present research focuses on analyzing the mesostructure of alkali leaching specimens obtained from distressed pavement. This analysis is conducted using X-Ray Computed Tomography (X-ray CT) and digital image processing (DIP) technologies. In order to assess the correlation between pore characteristics and alkali leaching, a parameter known as the critical pressure difference (CPD) is defined and calculated to quantify the leaching ability. The results show that alkali leaching cores (ALC) have a higher number of voids compared to Normal Cores (NC), particularly for voids of larger volume. Inadequate compaction effort induces vertical connectivity of voids in the alkali leaching pavements, thereby impeding the movement of alkaline solution. A sensitive porosity interval around 4.5 ∼ 5.5 % is found, the DGAC with larger porosity will easily occur leaching phenomenon in the certain CPD section. The correlation between the porosity and the CPD is also identified, indicating that the porosity is the main inherent factor in alkali leaching.

Effect of grouped L-shape rebar connectors on the shrinkage behavior of UHPC overlay cast on hardened NSC substrate

Ultra-high performance concrete (UHPC) overlay deployed in concrete bridge deck pavement exhibits a high amount of shrinkage that can lead to warping and debonding from the substrate of normal-strength concrete (NSC). This paper is to use grouped L-shape rebar connectors as a solution to alleviate the warping and debonding of the UHPC overlay which is cast on the NSC substrate. The rebar connectors are designed to be post-installed vertically in the hardened NSC substrate, and the rest part of the connectors are anchored in the UHPC overlay after the UHPC casting. In this study, an outdoor UHPC-NSC composite slab test was carried out, and two types of UHPC materials with distinct autogenous shrinkage were produced to cast the overlay. Different schemes of the rebar connector layout with various installing rates were performed. The restrained shrinkage of the UHPC overlay was monitored by the embedded strain sensors, and the UHPC overlay's long-term warping behavior was evaluated. In addition, a numerical model was established considering the shrinkage and creep of UHPC, the contact between the UHPC and the NSC substrate, and the concrete-to-rebar interaction. The results show that the grouped L-shape steel rebar connectors significantly affect the restrained shrinkage of the UHPC overlay by increasing the degree of restraint to the UHPC overlay by 13%-38%. The grouped L-shape steel rebar connectors are proven effective in alleviating warping and delamination in the UHPC-NSC composite slabs. Therefore, the use of grouped rebar connections is feasible in bridge deck pavement engineering.

Electrode Layout Optimization and Numerical Simulation of Cast Conductive Asphalt Concrete Steel Bridge Deck Pavement.

In order to obtain the optimal electrode layout and ice melting effect of cast conductive asphalt concrete steel bridge deck pavement, firstly, pouring conductive asphalt concrete was prepared; secondly, different electrode materials and layout methods were selected to test the heating rate of the specimen from start to 120 min, and the electrode materials and layout methods were optimized. Then, the finite element analysis software ANSYS was used to build the model for heating and ice melting simulation, and the indoor test was used to further verify the ice melting effect of the cast conductive asphalt coagulation with or without the insulation layer. Finally, the thermal-structural coupling analysis of cast conductive asphalt concrete steel bridge deck pavement was carried out using ANSYS finite element software. The results showed that the stainless steel electrode material had the best heating effect, and the electrode thickness in the range of 0.1~3mm had no effect on the heating effect. The intermediate heating rate of the upper surface of the stainless steel sheet electrode cast conductive asphalt concrete in the left and right external electrodes was 8 °C/h, while the intermediate heating rate of the upper surface of the stainless steel mesh electrode cast conductive asphalt concrete was 12.9 °C/h. The layout of the left and right buried stainless steel metal mesh was able to effectively improve the snow melting efficiency; ANSYS finite element ice melting simulation was used to obtain the variation law of ice melting efficiency and a temperature field of cast conductive asphalt concrete. The indoor ice melting test showed that when melting the same thickness ice layer at 50 V voltage, it took 240 min with an insulation layer and 720 min without an insulation layer, which was three times that of the ice with an insulation layer, which further verifies the superiority of its ice melting effect. The most unfavorable load position of pavement under load and temperature field was determined. The maximum tensile stress and compressive stress of the pavement surface were transverse, and the maximum shear stress of the pavement bottom was transverse.

Interlayer Shear Characteristics of Bridge Deck Pavement through Experimental and Numerical Analysis.

In order to study the interlayer shear behavior of bridge deck pavement, a numerical simulation was conducted to analyze the influence of varying interfacial conditions on shear stress at the bottom of pavement layers under the moving loading effect. Moreover, the shear strength of the different adhesive and waterproof adhesive materials was evaluated by conducting laboratory tests. The results showed that improving the bonding condition at the upper interlayer led to the reduction of the shear stress at the bottom of the pavement layers. With the increase of the friction coefficient of the upper interface to the full bonding state, the resulting shear stress at the bottom of the upper layer declined to the lowest value, which was about 35% of that of the full slip state. When the lower interlayer was in the full slip or partial bonding state, the resulting shear stress at the bottom of the lower layer decreased linearly with the increase of the friction coefficient of the upper interlayer. Moreover, once the contact state of the upper interlayer reached the full bonding state, the resulting shear stress at the bottom of the lower layer reached the minimum, which is about 88% of that of the full slip state. To improve the integrity and shear resistance of the bridge deck pavement structure, interlayer bonding should be strengthened. In this regard, the resin emulsified asphalt was determined as an appropriate adhesive material to be applied at the upper and lower interlayers. In addition, interlayer shear bond strength, regardless of the type of adhesive materials, was decreased with increasing temperature. Finally, statistical analysis results indicated that all factors of structure type, type of adhesive material, and temperature statistically have a significant effect on interlayer bond strength. The findings of this study could provide a theoretical basis and experimental support for improving the interlayer design and construction in the concrete bridge deck pavement structure.

Bonding performance evaluation on WTR-APAO composite modified asphalt as waterproof adhesive layer for concrete bridge

• The preferred concrete surface depth was 0.88 mm, and the gravel covering rate at 70 %. • The optimal dosages of WRAMA, WRMA, and SMA were 1.7 kg/m 2 ,1.2 kg/m 2 and 1.2 kg/m 2 . • WRAMA has higher bonding performance than WRMA and SMA at mid and high temperatures. • WRAMA shows good resistance to water immersion, freeze–thaw cycling, and aging. • The material cost of WRAMA is 30% lower than SMA based on economic comparison. Insufficient bonding at the waterproof adhesive layer (WAL) between the concrete bridge deck and asphalt pavement surface often leads to distress on the bridge or its surfacing pavement. This study proposes a relatively novel material, WTR (Waste Tire Rubber)/APAO (Amorphous Poly Alpha Olefin) composite modified asphalt (WRAMA), as WAL and evaluates its bonding performance compared to the commonly used interlayer SBS modified asphalt (SMA) and waste tire rubber modified asphalt (WRMA). The bonding performance was evaluated using straight shear tests and pulling out tests. Firstly, the optimal concrete surface chiseling depth was explored and determined at 0.88 mm, corresponding to 2 rounds of chiseling on the concrete surface. Then the preferred gravel coverage rate was set at 70 %, and optimum asphalt dosages were determined at 1.7 kg/m 2 , 1.2 kg/m 2 , and 1.2 kg/m 2 for SMA, WRMA, and WRAMA, respectively. While all three asphalts show good impermeability at their preferred dosage, WRAMA has the highest shear and pulling strength. Secondly, the bonding performances of investigated asphalts were evaluated and compared under controlled environments, including water immersion, temperature, free-thaw cycle, and aging. The results showed that WRAMA has the slightest temperature sensitivity but the least moisture resistance than SMA and WRMA. However, the shearing and pulling strength of WRAMA after freeze–thaw and water immersion was around 0.45 MPa, still higher than SMA (around 0.40 MPa) and WRMA (around 0.39 MPa). All three asphalts have decent resistance to aging. Thirdly, a preliminary economic analysis was conducted, and the results show that the material cost of WRAMA is around 66 % of SMA. Considering the WRAMA makes use of wasted tire rubber, this research reveals that the proposed WTR/APAO composite modified asphalt is potentially a cost-effective and environmental-friendly waterproof adhesive layer.

Properties of Different Waterproof Bonding Layer Systems for Cement Concrete Bridge Deck Pavement

The performance of waterproof bonding layer systems significantly affects the service life of concrete bridge deck pavement. This article aims to compare the bonding properties and composite structure mechanical properties of different waterproof bonding layer systems in bridge deck pavement to recommend appropriate structures based on service conditions. To fulfill this objective, four kinds of waterproof bonding material composite systems were designed, and test samples were fabricated. Then, the waterproof bonding layer properties were studied by penetration resistance tests, scalding resistance tests, and corrosion resistance tests. Pull-off tests were conducted to compare the bonding properties. Then, dynamic modulus tests, Hamburg wheel tracking tests, and static load creep tests of composite structure specimens were implemented to evaluate the dynamic and static mechanical performances and water-temperature stability. The findings showed that the four schemes had good impermeability. The pull-off strengths of scheme III at 25 °C were about 2.5-, 2.5-, and 4-times those of schemes I, II, and IV, respectively, and the pull-off strengths at 50 °C were about 1.6-, 2-, and 1.6-times those of schemes I, II, and IV, respectively, and the bonding performances and dynamic modulus of different schemes were ranked as follows: III > I > II > IV. The results of the Hamburg wheel tracking test were consistent with the static load creep test. The high-temperature stability of scheme IV was the best, while the stabilities of scheme III and I were better than that of scheme II. In conclusion, the scheme of concrete bridge deck pavement can be selected based on the environmental conditions and traffic load, and schemes III and I should be considered first. The findings of this research could provide technical support for the future design of bridge deck waterproof bonding systems.

Study on the Influence and Law of Waterproof System Design Factors on the Typical Stress of Bridge Deck Pavement

To improve the structural design rationality of cement concrete bridge deck pavement systems and reduce diseases such as interlayer displacement and rutting in the early stage of bridge deck use, this paper studies the influence and law of the coupling effect of various factors of the waterproof system on the typical stress of bridge deck pavement and determines the best structure combination for the bridge deck pavement structure. A finite element model was established by using commercial software to simulate the mechanical response of different types of waterproof bonding layer, waterproof leveling layer, and impervious structure layer under different parameters. The simulation results show that when the thickness of the pavement layer was 8 cm, the maximum shear stress of the pavement layer occurred in the middle of the wearing course and the junction between layers. When the pavement layers were continuous, the maximum strain of the waterproof bonding layer with the “rubber asphalt + protective plate” structure in the transverse and longitudinal directions was the largest. When the waterproof leveling layer was cement concrete, the structure bore a large amount of stress and easily produced cracks, resulting in water damage. High-density water-based asphalt concrete with a low permeability coefficient can reduce the interlayer shear stress and effectively ensure the interlayer bonding effect. On this basis, the following bridge deck pavement structure was proposed: waterproof system + multifunctional waterproof layer + load-bearing structure layer + surface functional layer.

Decision Method of Bridge Deck Pavement Maintenance Based on the Decision Maker’s Objective

The performance of reinforced concrete bridge deck pavement will be gradually reduced with the increase of operation time, so the reasonable maintenance measures should be taken to ensure the performance and safety of the bridge structures. The objectives and their hierarchical structures from both state position and enterprise position of the decision makers in bridge engineering decision-making problems were discussed. By the existing deterioration model, this paper studies the bridge operation safety maintenance strategy, establishes the mathematical model of the influence of different degrees of maintenance measures on the structural performance, combines with the cost-benefit theory, establishes the maintenance risk decision criteria for the decision makers with different objectives, and makes the decision on the selection of the bridge deck pavement scheme based on the enterprise position through an example.

Analysis of alkali leaching mechanism on as-built cement concrete bridge deck pavement

A new distress type, namely alkali leaching, was recently observed to have developed on an as-built dense-graded asphalt concrete (DGAC) paved on a cement concrete bridge deck in China. Not only does alkali leaching affect the aesthetic appearance of the cement concrete bridge deck pavement (CCBDP) due to the distinctive color contrast, it also creates a potential threat to the service life of the bridge. In this paper, an alkali leaching distressed section of a CCBDP in Shaanxi Province (China) was studied. The study results indicated that whitish spots cannot be removed by natural water. In situ pH measurements indicated highly alkalinine materials appear on the surface of pavement layers. Based on these findings, the formation mechanism of alkali leaching on CCBDP was analyzed. The corresponding results showed that the main mineral of alkali leaching was Calcium Carbonate (CaCO3). Under wet conditions, rainwater infiltrates into the cement bridge deck from the sides of the pavement. Continuous exposure to moisture or humid environments facilitates the subsequent hydration to generate Ca(OH)2, which is the alkaline source for alkali leaching. The generated Ca(OH)2 migrates with rainwater to the pavement surface through capillary action. With the repeated circles of wet and dry conditions, the in-situ carbonation products lead to formation of alkali leaching on the pavement surface.

Cold Area Asphalt Concrete Deck Pavement Technology Research

As the problem of asphalt concrete bridge deck pavement is becoming more and more serious, how to improve its road performance has become the focus of the study. As the lack of shear strength and bond strength between layers, flaking, raveling and other diseases were occurred on steel bridge deck asphalt pavement. This paper combines the common damages of bridge deck and asphalt concrete pavement in cold area of northeast region, focuses on the analysis of the cause of asphalt concrete pavement damage causes, puts forward preventive measures and recommendations, and present the bridge deck pavement structure in cold area combined with the engineering practice. The research results can effectively guide the construction of bridge deck pavement.

Thermal response analysis of reinforced concrete box girder during hot-mixed asphalt mixture paving

Hot-mixed asphalt (HMA) concrete has been extensively used in the concrete box-girder bridge deck pavement due to its excellent performance and driving comfort. Nevertheless, during HMA concrete construction, the high paving temperature may disturb the thermal field of the bridge, thereby causing the significant thermal response throughout the box girder. Therefore, this research aims to investigate the temperature behavior and thermal stress of a reinforced concrete box girder segment during HMA concrete paving. The transient thermal field theory and element deletion method were first adopted to establish a three-dimensional finite element model of a reinforced concrete box girder segment and simulate the dynamic paving process, respectively. Subsequently, the bridge monitoring data was used to validate the thermal field model and then the temperature distribution analysis was conducted. Finally, the thermal stress in the bridge was studied in cross-sectional area. Results demonstrate that the vertical temperature of the concrete box-girder during the paving process is declined with the increasing vertical distance to SFRC leveling layer, and its highest value occurs at 36min after starting to paving. Furthermore, in the vertical direction, the west web-plate is subjected to compressive stress at locations of two ends and tensile stress at locations of the middle. Meanwhile, the thermal stresses undergo a decline trend after short-term growth both in the box and flange slab in the transversal direction.

Interlaminar Bonding Properties on Cement Concrete Deck and Phosphorous Slag Asphalt Pavement.

The slippage damage caused by weak interlaminar bonding between cement concrete deck and asphalt surface is a serious issue for bridge pavement. In order to evaluate the interlaminar bonding of cement concrete bridge deck and phosphorous slag (PS) asphalt pavement, the shear resistance properties of the bonding layer structure were studied through direct shear tests. The impact of PS as a substitute of asphalt mixture aggregate, interface characteristics, normal pressure, waterproof and cohesive layer types, temperature and shear rate on the interlaminar bonding properties were analyzed. The test results indicated that the interlaminar bonding of bridge deck pavement is improved after asphalt mixture fine aggregate was substituted with PS and PS powder, and the result indicated that the shear strength of grooved and aggregate-exposed interfaces is significantly higher than untreated interface, the PS micro-powder or anti-stripping agent can also improve the adhesion between layers when mixed into SBS asphalt. This study provided important theoretical and practical guidance for improving the shear stability of bridge deck pavement.

Study on influence factors of asphalt mixtures pavement blistering on Portland cement concrete bridge deck

ABSTRACT This paper aims to discuss the blister properties on Portland cement concrete bridge deck pavement. The deformation characteristic and mechanism of blister are investigated quantitatively by an automatically developed pressurised blister simulation tests and Digital speckle correlation method (DSCM). Two different types of asphalt mixtures (SMA-13 and AC-13) and three different types of asphalt waterproof bonding materials (SBS modified bitumen, rubber bitumen, SBS modified emulsified bitumen) were studied in this paper. The air void of asphalt mixture, test temperature and material types were analysed to explore the influence on the blister deformation. In addition, the initial surface absorption test (ISAT) is used to quantitatively assess the influence of air void. The results indicate the air void of asphalt mixture and the test temperature have different influences on the blister damage performance. The blister failure mode has a direct relationship with air void. For the same asphalt waterproof adhesive layer, SMA-13 asphalt mixture is better than AC-13 asphalt mixture in the resistance of blister deformation.

Interlaminar Performance of Waterproof and Cohesive Materials for Concrete Bridge Deck under Specific Test Conditions

AbstractThe performance of waterproof and cohesive material significantly affects the service life of concrete bridge deck pavement. In this paper, six kinds of waterproof and cohesive materials in...

Deformation characteristic and mechanism of blisters in cement concrete bridge deck pavement

The waterproofing membrane applied on cement concrete bridge deck usually experiences small uplift blisters, which leads to serious corrosive problems when water infiltrates into the bridge deck through the blister area. It is very important to reveal the formation and propagation of the blister for decreasing the damage of bridge deck pavement. In this paper, the environmental simulation blister test is proposed originally, and MatchID-3D (MTI-3D) structural deformation analysis system is adopted to measure the blister deformations. The deformation characteristic and mechanism of the blister are investigated. The test results show that the stages of blister deformation can be determined according to the deflection rate. The deflection deformation of the blister is a rapid process happening mainly in the third stage, while the debonding deformation is a relatively stable and long-term process. The test temperature, initial debonding aperture, and water have great influences on the failure time, meanwhile the former two factors also affect the total debonding length seriously. An improved blister test method is developed in this paper to accurately study the blister deformation under different environmental conditions, which helps to determine effective measures to eliminate the blister in bridge deck pavement.

Study on evaluation method of mud-pumping of cement concrete bridge deck pavement

Mud-pumping is one of major distresses of concrete bridge deck pavement, which not only influences the riding comfort of vehicles but also affects the appearance of bridge pavement and endangers the whole bridge structure. Although many methods have been used to assess the mud-pumping distress, most of them remain in the qualitative assessment. Relevant researches about testing methods and quantitative assessment approaches are seldom studied. In this paper, Initial Surface Absorption Test (ISAT), X-ray CT technology, and fractal theory are adopted to assess mud-pumping pavement and study the effect of capillary force on the mud-pumping distress. In addition, the influences of voids distribution characteristics on the capillary water absorption capability are discussed. The ISAT result shows that three significant parameters of mud-pumping cores, such as the capillary water absorption mass, the capillary water absorption coefficient, and the ratio of capillary voids to air voids, are markedly different from those of the non-pumped cores. The mud-pumping cores had a relatively higher void ratio of volume ≤ 0.1 mm3, and lower complexity of void. Quantitative evaluation indexes for mud-pumping distress are recommended by this paper.

Study on the Anti-Cracking of GFRP Bars Asphalt Concrete Bridge Deck Pavement under the Vehicle Load

the mechanical analysis of bridge deck pavement is limited at home and abroad.As is known to all,when we referred to the load-carrying capability of a bridge, the deck pavement is surely the weakest part. It is necessary to analyze the distribution of stress on bridge deck pavement, then design the pavement reasonably. In this paper, the model of bridge deck structure can be analyzed using solid model of bridge deck established in the principle of the finite element software. The analysis mainly includes two sides: one is analyzing the tensile stress of the deck caused by vehicle from Horizontals and verticals;the other is about finding the position of the most unfavorable load, and replacing corrosion-resistant GFRP with common steel ,then establishing GFRP reinforced asphalt bridge deck solid model. The author will analyze the setting states and the most suitable location of GFRP bras under the vehicle load on the bridge deck. At last we make the conclusion that the GFRP bars can effectively undertake the stress to prevent cracking.

Research on Interfacial Shear Characteristics of Crumb Rubber Modified Asphalt Concrete Bridge Deck Pavement Structure

The interfacial shear characteristics and the influence of overloading on the structure of SBS (styrene-butadiene-styrene) and crumb modified asphalt bridge deck pavements are studied in this paper. Crumb rubber modified asphalt bridge deck pavement is applicable to Inner Mongolia cold regions. These pavements are evaluated through the indoor asphalt concrete bridge deck pavement interfacial shear contrast test. The results indicate that for the interfacial shear strength between asphalt pavement structure of lower layer and concrete bridge deck pavement, the strength of SBS modified asphalt pavement is slightly greater than the crumb rubber modified asphalt pavement. For the interfacial shear strength between asphalt pavement structure of upper layer and lower layer, the strength of crumb rubber modified asphalt pavement under the overload less than 50% is slightly greater than SBS modified asphalt pavement shear strength. The interfacial shear strength between the lower layer and the concrete bridge deck pavement of two kinds of modified asphalt pavement structure is less than the interfacial shear strength between the upper layer and the lower layer. The interfacial shear deformation of crumb rubber modified asphalt is greater, and the interfacial shear deformation between the lower layer and the concrete bridge deck pavement of two kinds of modified asphalt pavement structure is less than the interfacial shear deformation between the upper layer and the lower layer under the vertical stress less than 1.05MPa. Finally, the shear stress of crumb rubber modified asphalt concrete bridge deck pavement structure under the standard load is calculated by the finite element software ABAQUS. Comparing and analyzing the experimental results shows that the bridge deck pavement meets the shear requirements.

고분말도 혼화재를 첨가한 삼성분계 시멘트 콘크리트의 내구성 평가

PURPOSES : The purpose of this study is to evaluate the durability of ternary blended concrete mixtures adding ultra fine admixture. METHODS : From the literature review, crack was considered as the main distress failure criterion on concrete bridge deck pavement. To reduce the initial crack development due to drying shrinkage, CSA expansion agent and shrink reduction agent were used to ternary blended concrete mixtures as a admixture. Laboratory tests including chloride ion penetration test, surface scaling test, rapid freeze & thaw resistance test, non restrained drying shrinkage and restrained drying shrinkage test were conducted to verify the durability of ternary blended concrete mixtures. RESULTS : Based on the test results, proposed mixtures were verified as high qualified durable materials. Expecially initial drying shrinkage crack was not occurred in ternary blended concrete mixtures with CSA expansion agent. CONCLUSIONS : It is concluded that the durability of proposed ternary blend concrete mixture was acceptable to apply for the concrete bridge deck pavement.