Portland Cement Concrete Slab Research Articles

PCC Slab Temperature Gradients as a Function of Structure and Environment Experience from the SHRP II R21 Composite Pavement Test Track

The Strategic Highway Research Program (SHRP) II R21 Composite Pavement Research Project test track constructed at University of California Pavement Research Center (UCPRC) ATIRC facility has yielded significant Portland cement concrete (PCC) temperature data over the nearly past two years of testing. The nine different test sections consisted of combinations of plain and hot mix asphalt (HMA) overlaid jointed plain concrete (JPCP) pavement sections of varying thicknesses. Over 135 thermo couples were placed at five depths and three locations within each slab and have been continuously monitored since test track construction. This paper will identify the changes in PCC slab temperature gradients as a function of PCC slab thickness (178mm and 127mm), HMA overlay thickness (114mm, 64mm, and 0mm) and type (Polymer modified and rubber). Results provide important information about the thermal insulation effect of HMA layer to reduce temperature gradients in PCC layers and provide experimental data for continued evaluation of the effects of reduced temperature gradients on PCC layer cracking performance.

Quantifying Effective Built-in Temperature Difference for Decades- Old Jointed Plain Concrete Pavements in Eastern Washington State

Fifteen Portland cement concrete (PCC) slabs from four Jointed Plain Concrete Pavement (JPCP) sections in the Long-Term Pavement Program (LTPP) located in eastern Washington State were studied in this paper. Dipstick-measured transverse deflection profile along with temperature measurements across slabs’ depths collected during falling weight deflectometer (FWD) testing were used in the study. The youngest section in the study was 24 years old at the time of testing. The objective was to characterize the total effective linear temperature difference (TELTD) and the effective built-in temperature difference (EBITD) in the slabs. EBITD is a temperature differential representing the combined effects of construction built-in, as well as long-term drying shrinkage, and creep equivalent temperature differences. Using ISLAB2000, several iterations were run for each slab to identify the TELTDs that would produce slab curvatures close to those measured in the field. For validation purposes, the found TELTDs were used in Westergaard’s closed-form solution for deflections in the transverse direction. Transverse profiles predicted by ISLAB2000 and Westergaard equations matched well. EBITD, was then obtained by simply subtracting the in-field measured temperature differential from TELTD. Variations of EBITDs were found among the four sections, ranging from +31 to -120 °C (55 to -215 °F). Multiple factors, such as structural features, material properties, construction conditions, and climatic conditions, were identified as influential for the predicted EBITDs.

A novel real-time structural acceleration-based methodology for detecting support loss under PCC pavement subjected to vehicle loading

ABSTRACT Support loss is a concealed distress in Portland cement concrete (PCC) pavements. This study proposes a real-time methodology to detect support loss under PCC pavements using structural acceleration responses. Full-scale tests were conducted under different support loss conditions. The sports utility vehicle (SUV), truck, and FWD were used. The results revealed that the main frequency of acceleration signals of PCC slabs under FWD and vehicle loads varied between 20~25 Hz and 10~15 Hz, respectively. When support loss occurs, both the acceleration amplitude and the signal energy within high-frequency range increase. By calculating the signal energy of acceleration response at slab corner (Scor) or longitudinal edge midpoint (Smid), support loss is indicated at slab corner when signal energy at Scor increases by about 90 times or signal energy at Smid increases by about 10 times. Additionally, by calculating the ratio of signal energy within high-frequency range to that within low-frequency range (ER) of acceleration signals at Smid, support loss at slab center is considered to have occurred when ER exceeds 3. To reduce costs, only one sensor can be placed at Smid. The proposed method has advantages of not requiring traffic closure, realizing real-time monitoring, and facilitating intelligent maintenance.

Perencanaan Tebal Perkerasan Kaku Jalan Raya Cadas - Kukun Kabupaten Tangerang

ABSTRACT Portland cement concrete pavement or more commonly called rigid pavement or Rigid Pavement, consists of a Portland cement concrete slab and a foundation layer (may or may not exist) on the subgrade. This concrete slab can use reinforcement or without reinforcement depending on the planning. This is different from flexible pavements where the stiffness of the pavement is obtained from the thickness of the subbase layers, the foundation and the surface layer. Because the most important thing is to know the load-bearing capacity of the structure, the factor that needs to be considered in designing concrete road pavements is the strength of the concrete itself. The varying strength of the subgrade or foundation has little effect on the structural capacity of the pavement (the thickness of the concrete slab). The subbase layer, if used under a concrete slab, is intended as a working floor and for drainage to prevent pumping. Pumping is the event of the release of water accompanied by subgrade grains through joints and cracks or on the pavement edge, due to deflection or vertical movement of the concrete plate due to traffic loads, after free water has accumulated under the concrete plate. Pumping can cause cavities to occur. under the concrete plate causing damage or cracks to the plate Key words: Rigid Pavement,Semen Portland,Pekerasan Lentur , Pumping.

Experimental Investigation on Strengthening of Geo-Polymer Concrete Slab with Bubble Technology

The bubble deck technology developed in Europe makes use of high-viscosity concave polyethene spheres to replace the ineffective concrete in the centre of the slab, therefore dwindling the dead weight and adding the effects of the bottom. This system is used in the concrete floor system. Concrete is good in contraction and hence is more useful in the contraction region than in the pressure region. The reduction in concrete can be done by replacing the pressure zone concrete. An experiment has been carried out to find out the effectiveness of plastic bubbles by replacing concrete in the pressure zone of Ordinary Portland Cement Concrete (OPCC) and Geo-Polymer Concrete (GPC) slab. Constituents named are cement, sand, and coarse aggregate for OPCC and for GPC cement is fully replaced with 70% fly ash, 15% GGBS and 15% glass powder. NaOH(12M) alkaline solution is added instead of water for GPC. In this design, M45 concrete blend is used to prepare both OPCC and GPC slabs. The trial blend is tested for compressive strength in 7 days and 28 days. A flexure test is done for 7 days and 28 days of curing of the beams. The procedure is repeated for beam samples with bubble mesh and bubble mesh along with shear underpinning. Relative analysis of the OPCC and GPC slabs is done to observe the chance reduction in tone-weight and cost-effectiveness. Analysis of the geste of the GPC beam in comparison with that of the OPCC beam is also carried out.

Study on Thermal Reflective Cracking of Asphalt Concrete Overlays on Concrete Pavements Under Moderate Temperature Variations Using Finite Element Model

This study investigated the effects of moderate daily temperature variations on reflective cracking in asphalt concrete (AC) overlays on Portland cement concrete (PCC) pavements using three-dimensional (3D) finite element (FE) modeling. The FE model consists of an AC overlay on top of PCC slabs, followed by aggregate base and subgrade. The year-round temperature variations were divided into discrete groups using a clustering technique and each group was applied separately in the FE model. The maximum stress and strain values associated with each temperature variation group were determined using the FE model and used as the driving force corresponding to the thermally induced damage in the AC overlay. The results show that the maximum stress and strain values in the overlay depend on the hourly temperature variation as well as the seasonal temperature profile. The daily temperature variation controls the deformation of the underlying PCC slabs, whereas the seasonal temperature profile determines the viscoelastic properties of the AC overlay. The estimated maximum tensile stress and strain values suggest that the AC overlay is primarily subjected to damage from repetitive thermal loading instead of one-time fracture events for moderate temperature variations. In addition, when the AC overlay is fully bonded to the PCC slabs, the thermal strains are much greater than the traffic induced strains, indicating a high possibility of thermal reflective cracking being the dominant damage mechanism for these cases.

Reflective crack initiation of asphalt overlays on jointed concrete pavement using finite element model

ABSTRACT In this study, a three-dimensional (3D) finite element model (FEM) consisting of an asphalt concrete (AC) overlay on top of jointed plain Portland cement concrete (PCC) slabs was developed to investigate the mechanism of the crack initiation of traffic-induced reflective cracking. Strain values at the bottom of AC overlay were the primary response obtained from the simulation results to represent the damage induced in the AC layer. Different bonding situations between the two layers, traffic load locations, material properties and thicknesses of the AC layer were taken into consideration. The analysis results show that the dominating strain for damage is dependent on the bonding condition between the AC and PCC layers. When the AC layer is completely bonded with the PCC layer, the damage will initiate firstly at the top of the joint corner between the PCC slabs to deteriorate the bonding, then the AC bottom will be susceptible to bending strain. It was observed that the most critical load location for modeling the case of fully bonded overlays is related to the AC thickness while in the case of partially bonded overlays, the most critical load location is always located on the top of one side of the PCC joint.

Evaluation of the Incorporation of Tire-Derived Aggregates (TDA) in Rigid Pavement Mix Designs

Owing to the extensive worldwide generation of solid wastes, such as rubber tires, and the resulting adverse environmental impacts, the incorporation of these waste materials in construction projects has become a widespread aim. However, concerns have arisen regarding the effects of rubber waste on the mechanical properties of Portland cement concrete (PCC) mixes. Thus, this study investigates the effects of replacing natural coarse aggregates with tire-derived aggregates (TDA). In PCC mixes, natural aggregates were replaced by 0, 10, 20, 40, 60, 80, and 100% TDA by volume, and the properties of these specimens were tested in the laboratory. The results obtained were then used as inputs for the KENPAVE software, to evaluate induced stresses, deflections, and cracking indices in rigid pavement slabs, with eleven different thicknesses, ranging from 200 to 300 mm in 10 mm increments. Stresses under different loading conditions decreased as PCC slab thickness and TDA content increased. Increased deflection and cracking indices resulting from adding TDA could be counteracted by increasing the PCC slab thickness by 10 mm. Moreover, environmental impacts and cost analyses were examined via PaLATE 2.0, which showed that the use of TDA could reduce energy consumption, harmful emissions, and material costs. Overall, this study indicates that the use of TDA in PCC mixes has benefits that can make it a good candidate for sustainable, ecofriendly rigid pavement construction projects.

Performance Evaluation of Ultra-Thin Wearing Course with Different Polymer Modified Asphalt Binders

Ultra-thin wearing course (UTWC) as an asphalt overlay is widely used in pavement maintenance for extending pavement service life. Researchers focused on improving and evaluating its performance, yet few researchers compare the performance of typical UTWCs. Moreover, some traditional asphalt mixture tests are improper for UTWC due to the thicknesses of UTWC, which is thinner than the traditional asphalt overlay. This study further evaluated the advantages and disadvantages of typical UTWCs. A series of tests were conducted to compare the comprehensive performance of three typical UWTC products, including SMA-10, Novachip-B, and GT-10. Moreover, this study improved the rutting test to evaluate its rutting performance more accurately. Rutting specimens of 20 mm thick and 50 mm thick composite specimens (20 mm UTWC + 30 mm Portland cement concrete slabs) were prepared. Two types of PCC slabs were used, including unprocessed PCC slabs and PCC slabs with preset cracks. The test results showed that Novachip-B showed the best water stability and weakest raveling resistance, while GT-10 showed the best fatigue and anti-skid performance. The rutting performance of UTWCs was reduced because of the influence of preset cracks. The rutting depth of GT-10 was only 60–90% of that of others, showing the comprehensive performance of GT-10 was better than that of others. These results provide a significant reference for the research and application of UTWC.

Influence on the Flexural Behaviour of High-Volume Fly-Ash-Based Concrete Slab Reinforced with Sustainable Glass-Fibre-Reinforced Polymer Sheets

Concrete structures provided with steel bars may undergo deterioration due to fatigue and corrosion, which leads to an increase in repair and maintenance costs. An innovative approach to eliminating these drawbacks lies in the utilisation of glass-fibre-reinforced polymer (GFRP) sheets as reinforcement in concrete structures instead of steel bars. This article relates to the investigation of the flexural behaviour of ordinary portland cement (OPC) concrete slabs and high-volume fly ash (HVFA) concrete slabs reinforced with bi-directional GFRP sheets. Slab specimens were cast with 60% fly ash as a replacement for cement and provided with a 1 mm-thick GFRP sheet in 2, 3 and 4 layers. The flexural behaviour of slabs reinforced with GFRP sheets was compared with that of the slabs reinforced with steel bars. Experiment results such as cracking behaviour, failure modes and load–deflection, load–strain and moment–curvature relationships of the slab specimens are presented. Subsequently, the nonlinear finite-element method (NLFEM) using ANSYS Workbench 2022-R1 was carried out and compared with the experimental results. The results obtained from the numerical investigation correlated with the experimental results. The experimental investigation showed that the HVFA concrete slabs reinforced with GFRP sheet provided a better alternative compared to the steel reinforcement, which led to sustainable construction.

Investigating the Influence of Joint Reinforcements of Portland Cement Concrete Slabs Under Asphalt Concrete Overlays on Vertical Deflections Using Accelerated Pavement Testing

Joint gaps between slabs in underlying Portland cement concrete (PCC) pavements are critical factors in the life span of asphalt concrete (AC) overlays. Therefore, being informed about the vertical deflections that may occur around the joints is important. In this study the joints were reinforced with three different materials: ethylene propylene diene monomer (i.e., rubber joint filler [RJF] reinforcement), bitumen-based sealant (i.e., rubber plate [RP] reinforcement), and steel plate (SP) (i.e., SP reinforcement), to limit the vertical movement of the underlying PCC. Tests were conducted at the accelerated pavement testing facility for two different AC overlay thicknesses, 50 mm and 100 mm, during 100,000 passages to investigate the influence of AC overlay thickness variations on slab vertical deflections and to also evaluate types of joint reinforcement on slab vertical deflections. For 50-mm thick AC overlay, the most effective joint reinforcements to prevent deformations caused by loading were RP, RJF, and SP; for a 100-mm thickness, this was determined to be RJF, SP, and RP, respectively.

Evaluation of the PCC slabs of the bus corridors of Anapolis according to its extension

The Brazilian law N° 12.587/12 on urban mobility, currently in effect, aims to ensure the improvement of accessibility, and the trafficability of people and cargo in cities, as well as integrate transport modes, and study mechanisms for infrastructure management. Cities with a population of more than 20,000 had to create their urban mobility plans, according to the requirements of the Ministry of the City. The objective of the plan is to conceive projects that aim to mitigate operational and functional problems in the transportation network within the municipalities. One of these cities that is creating a mobility plan is Anápolis-GO, where its plan includes the implementation of bus lanes on the main avenues of the municipality. In these corridors, there was the substitution of the flexible pavement by slabs of PCC (Portland cement concrete), at the boarding and alighting points, due to the sudden braking events and occasional acceleration. Given this scenario, the study aimed to analyze the stopping distance at these locations, as a function of road speed and braking rate, to assess whether the length of these slabs would be sufficient to what was proposed. In addition, it was sought to monitor the pavement against the performance of the PCC slabs, given the incident loads of braking and acceleration, as well as the performance of the flexible pavement, predicting the possible consequences and/or pathologies that may occur due to the operation, since the existing traffic in the corridors should be compatible with that of a high-speed road.

Non-destructive ultrasonic evaluation of construction variability effect on concrete pavement performance

It is commonly recognized that non-uniformity of as-constructed Portland Cement Concrete (PCC) pavement may negatively affect long-term pavement performance. Conventional wisdom states that PCC thickness deficiency is the most important factor causing premature pavement failures. To address it, transportation agencies often impose strict penalties for not meeting the designed slab thickness requirements, thus contractors build slightly thicker slabs to avoid fines. However, other aspects of construction variability on pavement performance are mostly ignored by studies because conventional methods for construction uniformity assessment fail to provide sufficient information to quantify their effect. This study utilized a non-destructive ultrasonic test to evaluate in-situ pavement construction variability. To investigate the correlation between construction variability and surface distresses, a combination of non-destructive ultrasonic thickness measurements and visual distress surveys were performed in highways prior to rehabilitation. PCC slab thicknesses and shear wave velocities were computed from recorded ultrasound signals. An in-depth statistical analysis was performed to investigate possible relations between thickness or shear wave velocity and distresses using various pavement performance parameters. The main results of this analysis illustrate the importance of material quality and uniformity control during construction, since alterations in material properties significantly influence the presence of distresses. Shear wave velocity variations significantly correlate to cracked and broken slab panels in two sections, and, more importantly, to any type of distress in all tested pavement sections.

Mitigating reflective cracking in composite pavements through the use of a ductile concrete interlayer

Reflective cracking of composite pavements refers to the phenomenon that cracks propagate from a deteriorated Portland cement concrete (PCC) slab to the newly constructed hot mix asphalt (HMA) overlay at locations where there are joints and cracks in the underlying PCC pavements. It is one of the predominant failure modes of composite pavements, often resulting in premature failure and limited service life of HMA overlays. To improve the resistance of composite pavements to reflective cracking, in this study, a new ductile concrete interlayer made of Engineered cementitious composite (ECC) was proposed and experimentally evaluated. ECC is a type of high-performance fiber-reinforced cementitious composites that features high tensile ductility, high fracture resistance, and high deformation capacity. It is expected that by constructing a thin ECC interlayer between exisiting PCC pavement and HMA overlay, reflective cracking can be prevented or significantly delayed. In the current paper, small lab-scale sandwich-type composite pavement specimens with and without ECC interlayers were constructed and tested under fatigue loadings that simulates repeated traffic loadings. The experimental result indicated that the ECC interlayer successfully suppressed reflective cracking and altered the failure mode of the composite pavement. As a result, specimens with ECC interlayers exhibited significantly (30 to 47 times) higher fatigue life as compared to the control specimens without interlayers. This result demonstrated that ECC interlayer is effective in reflective cracking mitigation.

Impact of base type on performance of rigid pavement: a case study

ABSTRACT Base layer stiffness, durability, permeability, and constructability are all significant factors that influence the performance of a concrete pavement system. The interaction between a concrete pavement and the underlying base layer(s) affects the response, including the distribution of stress, strain and deflection, of the pavement system to traffic loads and environmental conditions. Subbase stiffness is also a significant influence on crack initiation in the PCC slabs. To verify these findings, a field investigation experiment was conducted on Interstate 90 in New York to compare the performance of two Portland Cement Concrete (PCC) sections, one with the NY Standard pavement design using Portland Cement Concrete on top of Cement Treated Permeable Base (CTPB), and the other with an alternate design using PCC on top of Dense Graded Aggregated Base (DGAB). Data collected from the two sections were compared, in particular the deflections due to temperature fluctuations and responses to Falling Weight Deflectometer (FWD) testing. The subgrade moisture content for both sections was similar. The DGAB sections provided equal if not better support for the PCC pavement which would result in longer-lasting pavement sections with lower construction and ownership costs than more expensive CTPB.

Integrated time-frequency wavelet analysis and impulse response filtering on SASW test for rigid pavement stiffness prediction

This paper employs an improved continuous wavelet transform (CWT) technique of Gaussian derivative function and impulse response filtering (IRF) in seismic surface wave analysis to improve data analysis in the Spectral Analysis of Surface Wave (SASW) method. Two procedures were used: first, the response spectrum of interest was chosen using a time–frequency wavelet spectrogram. Then, noisy distortions were eliminated by utilizing a time–frequency wavelet and impulse response filtering. The outcomes show that the SASW method is able to identify the surface wave velocity which coincides with the dynamic stiffness parameters of Portland Cement Concrete (PCC) slabs. The values of surface wave velocity increased during the curing stage, and in situ measurement of wave velocity could be helpful in determining the degree of curing. A good congruence has been demonstrated between the stiffness of PCC obtained from SASW measurements vis a vis that obtained using the American Concrete Institute (ACI) formulation.

Evaluation of skid resistance of pervious concrete slabs under various winter conditions for driver and pedestrian users

Skid resistance of pervious concrete (PC) in comparison with traditional portland cement concrete (PCC) was investigated in the laboratory and in the field. Dry, wet, and iced PC surfaces were tested using the British Pendulum Tester (BPT) with two rubber sliders to represent driver and pedestrian users. Also, iced PC surfaces were treated with de- and anti-icing chemicals and then tested using BPT. Skid resistance values were recorded as the British Pendulum Number (BPN). PC slabs cast from one mix design in three compaction levels revealed that minimal correlation existed between PC porosity and BPN. Laboratory-cast PC slabs showed 23%, 27% and 97% higher BPN values relative to PCC slabs under dry, wet and icy surface conditions, respectively. After one icing event, the one-time application of anti- and de-icing agents on PC slabs improved their friction to the allowable BPN level using both MgCl2 and CaCl2. Field testing of five PC installations with various mix designs and surface conditions showed similar or slightly higher BPN than adjacent PCC slabs. Overall, the laboratory testing in this study showed it is possible to produce PC with significantly higher skid resistance relative to traditional concrete, the field testing revealed the importance of regular maintenance, aggregate type and mixture design on the skid resistance of pervious concrete.

Numerical analysis of rehabilitated concrete pavement using crack-and-seating technique

ABSTRACT Crack-and-seating is a Portland cement concrete (PCC) pavement rehabilitation technique that has been practically used to mitigate reflective cracking, however, the mechanism is not well understood. This study applied the coupling discrete-continuum modelling method to a field project, which is aimed to evaluating the effect of hammer-introduced crack on the stress at the tip of joint and at the tip of crack that control the reflective cracking of a rehabilitated PCC pavement with asphalt concrete (AC) layer. Particle Flow Code (PFC) was used for modelling asphalt overlay and the fractured PCC pavement while Fast Lagrangian Analysis of Continuum (FLAC) was used for modelling base and subgrade soil. The numerical simulation and analysis has validated that crack-and-seating can effectively reduce the shear stress at the tip of joint. Reducing the distance from the location where the hammer-introduced crack is introduced to the joint can effectively reduce the shear stress, and such distance is recommended to be 0.1–0.2 m. When the hammer-introduced crack’s length is 0.225 m, that is, the tip of crack is 1/10 of the thickness of PCC slab distant from the PCC slab surface, reflective cracking that would ultimately occur in the AC overlay can be effectively mitigated.

Reflective cracking from thermal loading in asphalt–concrete composite pavements

Composite pavements made from a hot-mix asphalt layer over a Portland cement concrete slab typically suffer from reflective cracking. Due to repetitive slab joint movements, concentrated stresses occur under the asphalt layer and propagate towards the surface. Recently, top-down reflective cracking has been observed in the field on pavements with no traffic. Previous studies have indicated that asphalt ageing may be the main cause of this problem. However, top-down reflection cracks may occur when upward curling of the concrete slab base creates a concentrated stress on top of the asphalt. Other design parameters such as thickness, stiffness or joint spacing may also influence this cracking behaviour. In the study reported in this paper, reflective crack propagation under thermal loading was investigated to identify potential factors that cause top-down reflection cracks. The results showed that top-down reflection cracks appeared only in composite pavements where the slab base had a low elastic modulus.

Analysis of the Behavior of SMA Mixtures with Different Fillers Through the Semicircular Bend (SCB) Fracture Test.

In most cases, stone mastic asphalt (SMA) mixtures placed in thin layers and subjected to stress develop early cracks (potentially resulting from being improperly affixed to the underlying layer, placed over previously cracked asphalt pavement, or placed over Portland cement concrete slabs). However, the filler used in SMA production is very influential on the performance of the mix. Fillers used in this type of mixture have a low plastic index or are inert (calcium carbonate or lime), so it is important to understand the effect of each material on the possible fissuring and cracking process of the SMA mixture. The objective of this study is to present an evaluation of the behavior of SMA asphalt mixtures with different types of filler and at different temperatures using the semicircular bend (SCB) fracture energy test. This research compares results between fracture energy and different types of filler in SMA asphalt mixtures at temperatures ranging from −10 to 25 °C.