Cement Concrete Pavement Slab Research Articles

An experimental study on dynamic response of cement concrete pavement under vehicle load using IoT MEMS acceleration sensor network

Understanding the dynamic response of pavements is crucial for comprehending pavement deformation and interaction mechanisms under vehicle load. There is a notable absence of monitoring systems that involve the in-situ embedding of acceleration sensors within full-scale cement concrete pavement slabs. This research introduces an IoT system designed for the monitoring of pavement vibration responses, with its deployment and installation executed within a field engineering project. By collecting and analyzing the pavement vibration responses to vehicle loads, the study investigates the time–frequency characteristics of vibration signals across various vehicle speeds, sensor depths, and lateral distances. The findings reveal that both the amplitude and main frequency of the vibration signal escalate with vehicle speed, whereas the embedding depth of the sensor impacts only the amplitude, leaving the main frequency unaffected. Through statistical analysis, it was determined that effective sensor spacing on cement concrete pavements should not exceed 120 cm to avoid significant signal attenuation, which on average reaches 50 % at a sensor spacing of 90 cm. These insights offer critical guidance for optimizing sensor layouts on cement concrete pavements and lay the foundation for future research on vibration-based damage detection and vehicle information analysis.

A New General Solution of Axisymmetric Elastic Space Problem in Pavement Engineering

The general solution of the axial symmetry elastic space problem in cement concrete pavement is an elementary question. Combining the Love method and the Southwell method, the Southwell operator was used in the variable selection process, the displacement function was introduced to express the displacement component by the Love method, the expression of stress indicated by the displacement function was obtained by combining the displacement components, geometric equations, and physical equations, then the stress was substituted into the equilibrium equation, the biharmonic equation of displacement function was obtained by mathematical operation, and finally, a new general solution of the axisymmetric elastic space problem in cement concrete pavement was obtained. According to the proposed general solution, mechanical calculation for a cement concrete pavement slab on Winkler foundation was carried out, the displacement curve at the top surface of the slab and the stress curve at the top, middle, and bottom surface of the slab were derived, and the results showed that the method is feasible in the calculation of cement concrete pavement. The general solution provided a new method for solving the axisymmetric elastic space problem of cement concrete pavement.

The verification of the possibility of alkalis penetration from the surrounding environment into the concrete pavement slabs

The short material service life of concrete is currently a frequently discussed topic, especially for newly constructed roadways with cement concrete pavement. This early degradation of cement concrete pavement slabs is a major problem that threatens the service life of sub-sections or the entire road. As some partial results demonstrate, a possible cause of this degradation can be seen in the surrounding road environment, namely the possibility of transferring aggressive substances to the concrete pavement slab. This paper is concerned with the verification of the possibility of the penetration of alkalis penetration from the surrounding environment into the concrete pavement slab by simulating the effect of different external conditions and environments.

INVESTIGATION OF SURFACE REFLECTIVITY OF CEMENT CONCRETE MODULAR PAVEMENT

One of the conditions for safe and comfortable driving on roads is a surface that is reflective and clearly visible at night. The luminance of a road surface depends on the amount of light falling on it and the reflectance properties of the road surface at any point. The reflectance of a road surface depends on its physical condition, age and type, the direction of lighting, and the conditions of observation. Different road surfaces may have various reflectance characteristics depending on the surface texture, materiality and binder. Experimental studies were performed on cement concrete modular pavement slabs that differ in color and texture of the surface. The analysis of the research results showed the differences between the reflective luminance characteristics of the surface of cement concrete modular pavement, taking into account the color of the coating, the texture properties of the coating surface and surface conditions. In the case of wet or damp concrete modular coatings, the reduced luminosity coefficient is about 60 percent lower than in dry ones. The reduced luminance coefficient of the light gray coating is about 38 percent higher than that of the darker shade coating (red and dark gray). The results obtained from the research are significant for street designers in choosing the type of pavement and designing street lighting.

Numerical Analysis on the Structure Design of Precast Cement Concrete Pavement Slabs

The performance of cast-in-place cement concrete pavement can be greatly influenced by the surrounding environment and the quality of construction, and it requires longer curing time before opening to the traffic. The precast cement concrete pavement has the potential to address the disadvantages of using the cast-in-place cement concrete as the pavement surface material, and it also provides an alternative solution for the rapid repair of pavement damage. The current study aimed to assess the influences of geometry of full-scaled precast concrete slabs with various load transfer joint types. A numerical analysis was conducted using the finite element method to analyze the mechanical responses of the single and double slabs in accordance with the elastic thin-plate theory and the Specifications for Design of Highway Cement Concrete Pavement. Under the premise of determining the most unfavorable load position for different mechanical parameters, the mechanical response regularity under the critical loads was determined. The precast concrete pavement slab with dimensions 4 m long, 3 m wide and 0.28 m thick exhibited better mechanical responses when considering the maximum deflection and flexural stress as the evaluation index. The results indicated that the variation of joint forms has marginal influences on the maximum deflection and displacement transfer coefficient. When considering the maximum flexural stress and load transfer coefficient of the precast slabs, the circular tongue-and-groove joint form was recommended for application.

Study on the Preparation and Performance of a Prefabricated Pervious-Cement-Based Concrete Pavement Slab

Based on the design of a prefabricated pervious composite cement concrete pavement slab, the interface properties and bending deformation properties of basalt pervious concrete (BPC) and PVA fiber base impervious concrete (PFBIC) composite specimens were studied. The effects of the different interfacial agents on the interfacial bonding performance were compared using a splitting tensile strength test and interfacial shear test. The deformation capacity of the composite specimens under bending load was tested using a three-point bending test, with the symmetry of the model considered and compared with the deformation capacity of the BPC specimen and PFBIC specimen. The results showed that the compressive strength of the BPC prepared using an orthogonal test reached 40.30 MPa, while the permeability coefficient was 2.41 mm/s. Different interface treatment processes determine the interface bonding properties. The best interface treatment method can induce the interface bonding strength to be higher than the strength of the BPC matrix itself, while the interface transition zone matrix will be denser without obvious microscopic defects. Under the bending tensile load, the ultimate bending stress reached 6.58 MPa and the maximum deflection in the midspan was 0.81 mm. As a protective layer, the PFBIC can alleviate the disadvantage of the insufficient strength of the BPC and can improve the bending ultimate bearing capacity of the BPC-PFBIC through its own stiffness.

Research of strength and condition of cement-concrete pavement on bridges by non-destructive methods

The article presents the results of determining the strength of non-destructive methods of cement concrete pavement on bridges. According to the results of the research, a differential curve, a reliability curve and the inverse value of the accumulated frequency of compressive strength of cement concrete are constructed. It is established that the cement concrete of the investigated objects corresponds to the strength class according to the normative documents. However, the results of visual, instrumental and thermal imaging inspection of areas on the bridges revealed a number of defects in the cement-concrete pavement and pavement slabs, which can lead to loss of the pavement structure strength. In particular, it was found that the destruction of the inspected reinforced concrete slabs of bridges mainly occurs under the influence of corrosion and loss of the working part volume of the steel reinforcement, unsatisfactory condition of the compensation seams on the supports. It is determined that cracks in reinforced concrete slabs occur due to low resistance of concrete to bending loads, due to which steel reinforcement is exposed to aggressive environments. In turn, it was proved that structural cracks in concrete occurred due to excessive loading, which led to overstrain of the structure, and non-structural cracks - due to internal stresses caused by thermal loads and various linear expansions of materials. Thermal imaging study revealed a significant difference in temperature in the pavement structural elements, which in the future leads to the destruction of cement-concrete pavement. It was found that the peeling of the protective layer of metal reinforcement on the studied bridges is caused by the phenomenon of electro-chemical corrosion.
 The experience analysis of cement-concrete pavement of the studied objects allows to prepare proposals for the construction of cement-concrete pavement of bridges and overpasses using modern materials, in particular, non-metallic reinforcement.

Precast system and assembly connection of cement concrete slabs for road pavement: A review

Prefabricated pavement is increasingly applied worldwide due to the rapid construction on-site. This paper presents a state-of-the-art review of the precast systems and assembly connection of concrete slabs, as well as the precast pavement features. The previous research indicates that: (1) both super-slab and Michigan systems are recommended with the satisfied road performance close to the cast-in-place; (2) flexible base material is suggested for the fabricated pavement for the satisfied leveling and stress distribution; (3) to prevent the voiding phenomenon of the fabricated pavement, the sand cushion course, dry mixed mortar or self-leveling mortar, and other flowable materials could be used for the secondary leveling of the base after the pavement splicing; (4) two-direction dowel bars are recommended for slab connections of the fabricated pavement, which helps to improve the load transfer capacity of the joints and enhance the durability of the fabricated pavement structure; (5) the sealing treatment of precast slab joints needs strengthening to reduce the impact of surface runoff on the base course; (6) the further research focuses are designing with functional, composite, mechanized, intelligent, lightweight, and flexible pavement slabs. Besides, pavement mechanical properties induced by temperature overlapping traffic loads need to be revealed. • The cement concrete pavement slab prefabrication system was summarized. • The joint treatment and connections between precast slabs were reviewed. • Technical features of the prefabricated concrete slabs were presented.

A study on the mix proportion of fiber-polymer composite reinforced cement-based grouting material

Cement-based grouting materials are widely used to repair slab hollows under cement concrete pavement slabs. However, the existing cement-based grouting materials fail to meet the needs of rapid penetration reinforcement. In this paper, a cement-based grouting material, which is reinforced by fiber-polymer composite and with excellent characteristics of high permeability and micro expansion, is proposed to repair slab hollows between the cement concrete slab and cement stabilized base. Firstly, take the fluidity, compressive strength and flexural strength as the evaluation indexes and determine the reasonable mixing amount of each component by single mixing tests. Secondly, take the water-cement ratio, early strength agent content, modified fiber content and VAE polymer content as object factors and optimize the mix proportion of the grouting material by orthogonal tests. The effectiveness of the proposed grouting materials is identified by indoor model tests, and the results show that the mechanical properties of the proposed materials (including compressive strength and flexural strength) are improved significantly compared with ordinary grouting materials.

Analysis of the Coupling Effect of Thermal and Traffic Loads on Cement Concrete Pavement with Voids Repaired with Polymer Grout

Under the repeated action of traffic and thermal loads, a cement concrete pavement slab may partially lose contact with its base course, and voids may develop underneath the slab. Such distress will greatly impact the pavement performance. To fill the voids and restore the base support to the slab, the technology of polymer grouting has been increasingly adopted in recent years due to its advantages of quick application and high efficiency. There is, however, a lack of research on the mechanistic responses and performance of such a repaired rigid pavement under coupled influences of thermal and traffic loads. Existing literature has mainly focused on normal cement concrete pavement structures (i.e., without polymer grouted voids). This study intends to fill the research gap by investigating the time-domain characteristics of thermal stress response of a cement concrete pavement with underlying voids filled with polymer grout, along with design traffic loads. The finite element method was adopted with a 3-dimensional nonlinear temperature field within the pavement. A program module was developed in the Abaqus FEA software environment for temperature effect analysis. It was found that under the coupling action of thermal and traffic loads, thermal stress had a greater influence on the critical slab stress at the slab corner than those at other slab locations. Through the comparative analysis before and after polymer grouting repair, the critical tensile stress at the slab corner under the vehicle and thermal loads can be effectively reduced. The polymer performance is stable after three years.

Hydrodynamic pressure distribution in saturated void beneath cement concrete pavement slab

ABSTRACT The void beneath cement concrete pavement slab (CCPS) is one of the common defects, which can cause the pavement cracking when heavy vehicle load is exerted on the pavement. The void expands when the water trapped inside erodes the inner surfaces of void circularly, bringing more cracks easily. Due to the close relationship with the erosion of the void, the hydrodynamic pressure distribution in saturated void beneath CCPS is investigated in this paper. Firstly, a theoretical expression of the hydrodynamic pressure in saturated void is proposed taking in account the law of mass conservation and the theorem of momentum. Secondly, the deformation patterns of the CCPS and the fluid-structure interaction (FSI) are discussed based on the proposed method. The results show that the hydrodynamic pressure and the water flow velocity in the void are overvalued while the rigid deformation pattern of CCPS is employed and the FSI is ignored. Finally, some influence factors are discussed. It is obtained that, both the maximum hydrodynamic pressure and the average velocity of water increase with the increase of the load amplitude, the vehicle speed and the void dimension. The conclusions are helpful for the prevention and maintenance of void beneath the CCPS.

Mechanical response analysis and optimization of snap on Prefabricated Concrete Pavement Slab

In this paper, a kind of assembled cement concrete pavement slab was numerical analysis to investigate the influence of the size of the tongue and groove joint on load transfer capacity between slabs and the maximum stress in the slab. And the load transfer capacity of the slab and the maximum stress in the panel of different sizes are optimized.

Influencing factors and experimental study on performance of composite cement-based grouting

The performance of grouting material directly affects the grouting effect under cement concrete pavement slab. In this paper. the factors affecting the fluidity, strength and bleeding rate of grouting materials are analysed by repeated tests. The test results show that the slurry with good suspension is not easy to be diluted by water and has certain waterproof performance; The water-cement ratio is in the range of 0.35 to 0.5, and the suspension is good and not easily separated; Incorporation of fly ash will cause early strength reduction and increase of slurry bleeding. It is recommended not to exceed 50% of cement. Finally,it is suggested that the strength of the grout should not be as high as possible, and the problem of strength development at the late stage of grouting and matching of the strength of the base layer should be fully considered.

Identification and detection of a void under highway cement concrete pavement slabs based on finite element analysis

For a city, the construction of a road is related to the development of economy, and the construction of a road includes maintenance of the road. Cement roads have been popularized in road construction due to their low construction cost and high strength, but at the same time, road problems have arisen. In order to solve and prevent the problem of voids under highway cement concrete pavement slabs, the acoustic vibration method was used for the detection of voids under highway cement concrete pavement slabs. This method was briefly introduced and analysed with finite element analysis. Then, excitation equipment and ABAQUS software were used to perform instance analysis on the section from K08-000 to K09-000 of G325 National Road. The results showed that there were three situations, including a mild void, normal void and serious void. The degree of abrupt change of the peak amplitude of the acoustic vibration characteristic curve increased with an increase in the severity of the void under the highway cement concrete pavement slabs. The void area was obtained through calculation of the sound pressure characteristic curve data based on the finite element model, with an error between 17.0 and 21.9%. However, in road maintenance projects, this error is acceptable. In summary, the acoustic vibration method based on finite element analysis can effectively detect the position of a void under highway cement concrete pavement slabs and estimate the area.

Summary of the Grouting Material for the Void Beneath Cement Concrete Pavement Slab

With the increase of vehicle load and the pavement’s service life, the cement concrete pavement’s diseases are also gradually increased. Among them, the empty beneath slab is the most common disease and main safety problem. And it has seriously affected the usability and durability of the road. Press-oar is the most effective treatment means for the void bottom slab, and it has high performance requirements for grouting materials. Therefore, several common domestic and international grouting materials are analyzed and reviewed. And their advantages, disadvantages and improvement methods are pointed out. This will lay a foundation for the development of slab bottom void grouting materials in the future.

Variations in the composition and relations between alkali-silica gels and calcium silicate hydrates in highway concrete

Alkali-aggregate reactions (AAR) are a form of severe concrete deterioration that can be found anywhere in the world. The rock type of aggregate is the crucial factor for AAR occurrence as well as for the chemical and morphological nature of their deleterious products – alkali-silica gels (ASG). The paper focuses on highway cement concrete pavement with aggregate composed of metamorphosed volcano-sedimentary complex rocks, such as proterozoic chert, black shale, spilite, and green schist, and alluvial sandy gravels. These petrographic types of aggregate were found to be potentially hazardous. The microchemical composition of ASG was analysed and compared to calcium silicate hydrates present in the vicinity of one another. The qualitative elemental composition of both is the same. Gradual variations of ASG within a single position and among different positions in cement concrete pavement slabs were monitored and compared.

Grouting Material Mix Proportion Test Research of Void the Old Cement Concrete Pavement Slab

The effective treatment of void cement concrete pavement slab through grouting technology is the important premise of ensuring the service performance of asphalt overlay engineer on cement concrete pavement. Based on the current problems of grouting technology, we did experimental studies on the mixing proportion of grout slurry and analyzed the effects of slurry composition and admixture type on mechanical properties including the strength, mobility, viscosity, expansion rate and bleeding rate of the slurry and on the service performance. Based on these, we put forward the control indexes for grouting slurry mix proportion determination which provided guidance for the design and construction quality control of grouting under the old cement concrete pavement slab.

Effect of Perlite on Thermal Conductivity of Self Compacting Concrete

Cement concrete pavement slabs used in highway construction are planer structures. Apart from regular factors considered in analysis of concrete pavements, temperature effects influence the slab size, joint spacing and temperature reinforcement design. The thermal performance of concrete pavement is governed by its thermal properties viz. coefficient of thermal expansion, specific heat and thermal conductivity. Studies have been undertaken to assess the thermal properties of normal concrete. The measurement of thermal conductivity for Self Compacting Concrete (SCC) has been proposed in this paper. SCC is a highly flowable and non-segregating concrete. SCC has the ability to flow through congested reinforcements efficiently irrespective of the structure geometry.An experimental program has been undertaken, to assess the thermal conductivity values for M-40 grade of SCC mixes with manufactured sand. Class C flyash has been used as a cement replacement material. Perlite has been used as fine sand replacement material. The thermal conductivity values were measured using Guarded Hot Plate method (ASTM C177) as recommended in ACI 122R. This paper is an attempt to present the experimental results obtained for thermal conductivity studies undertaken on M-40 grade of SCC with optimized flyash dosage and perlite dosage.

Influences on the Axle Load Stress of the Cement-Concrete Pavement Structure Caused by the Crack or Cutting Crack of the Semi-Rigid Base

Some horizontal cracks will appear during the strength formation of the semi-rigid base, for the influences of dry shrinkage and temperature shrinkage exist, so the engineers often adopt the manual method of equidistant cutting crack to avoid the irregular cracks. In order to analyse the influences on the axle load stress of the cement-concrete pavement slab which caused by the width and position of the base cracks or cutting cracks, the 3D FEM was used to study them under the different working conditions considering the crack, width and position. By the above research, the results show the existing cracks affect the integrity and continuity of the pavement structure; The crack width has no large influence on the stress of the pavement slab, while the base stress decreases apparently with the increasing width, and it becomes stable finally; The stress of the pavement slab is maximum when the crack or cutting crack is located in the middle, while it's small when the crack or cutting crack is located in the one fourth of the pavement slab.

Experimental Analysis of Stress in Cement Concrete Pavement with Base Cracks

AbstractIn order to analyze the stress varieties in cement pavement slabs caused by load with the existence of base cracks, the influences of moduli, crack locations and quantities of semi-rigid base and lean concrete base, thickness of cement concrete slab and size of load and other factors on the load stress of cement concrete pavement slab were analyzed through experimental simulation methods. The analysis result indicates that: (1) The road surface deflection increases with the number of base cracks increasing; (2) The tensile stress at the bottom of concrete slab decreases with the increase of base modulus and slab thickness, the increase in slab thickness more substantially minimizes stress than does the increase in base modulus; (3) The stress of concrete slab increases sharply with the presence of base cracks, and the slab bottom tensile stress increases with the number of base cracks increasing; (4) The load increase is an important factor causing load stress increase; so overload must be strictl...