Pervious Concrete Research Articles

Optimization of mechanical properties of pervious recycled concrete using polypropylene fiber and waterborne epoxy resin

Although there are many potential applications for pervious concrete (PC) in alleviating urban waterlogging, noise effect, and heat island effect, its porous nature also means that it has a lower strength than conventional concrete. This study strives to improve the mechanical properties of PC considering conventional PC has mechanical flaws. The optimum mix design for PC using recycled coarse aggregate (RCA), fly ash (FA), and polypropylene fiber (PPF) was first researched and selected based on the orthogonal design technique, and the carbon emission from the production end of raw materials was assessed; Second, the influence of waterborne epoxy resin (WER) modification on the permeability and strength of PC was examined. The results of the orthogonal experimental study demonstrated that adding RCA significantly increased the compressive strength of PC while just marginally affecting the permeability indices. To achieve more than 30 MPa compressive strength, the optimum mix design for PC incorporating RCA, FA, and PPF was established (i.e., 15% target porosity, water-binder ratio 0.31, RCA replacement rate 40%, FA content 5%, and PPF volume content 0.11%). The greenhouse gas analysis revealed that this mixture of 50% RCA and 15% FA emits 41.77% less CO2 than the control mix. The use of WER enhanced the mechanical properties of pervious recycled concrete (PRC) by first improving the pore structure at the microscopic level. The findings of the study may serve as a foundation for producing high-performance green PC.

Sustainable ecological pervious concrete (SEPC) based on modified corn-cob coarse aggregate: Crushing morphology, strength, pore properties, and durability

In terms of agricultural products, corn is the most abundant crop in the world, yet a significant portion of its cobs are thrown away each year, which is a terrible resource waste. This study uses modified corn-cob coarse aggregate (MCCA) and recycled aggregate (RA) to prepare sustainable ecological pervious concrete (SEPC). Five different substitution rates (0%, 25%, 50%, 75%, and 100%) are designed to investigate the effect of substitution rate on the crushing morphology, strength, pore properties, and durability of SEPC. The results show that the saturated water absorption of MCCA is 45.4% and its numerical tube pressure reaches 0.9 MPa. The test results show that the mix of MCCA reduces the compressive strength of SEPC but is beneficial to improve the stress state of SEPC by increasing its continuous porosity, planting opening size, frost resistance and resistance to sulfate erosion. At 50% replacement rate, comprehensive performance of SEPC is at its best. Specifically, test group with 50% MCCA substitution rate exhibits the lowest rate of compressive strength loss during freeze-thaw cycles (7.58%) and the best corrosion resistance coefficient (97.97%) when subjected to sulfate erosion. Therefore, MCCA can be used as a sustainable and ecological lightweight aggregate to improve some properties of pervious concrete.

Soft computing to predict the porosity and permeability of pervious concrete based on mix design and ultrasonic pulse velocity

ABSTRACT The present study explores the potential of machine learning to predict the porosity and permeability of pervious concrete constructed on mix parameters (compaction energy, aggregate-to-cement ratio and aggregate size) and ultrasonic velocity. The prediction models use non-destructive measurements and mixed design variables, which can help the construction sector apply the models without any theoretical expertise. The study uses 225 data samples from an experimental study. This study used six machine learning algorithms, namely, linear regression, artificial neural networks, boosted decision tree regression, random forest regression, K-nearest neighbour and support vector regression, to determine the best predictive model. The results show that the ANN model is the best technique for predicting the porosity of pervious concrete (R2 = 0.9502 for training datasets and R2 = 0.8958 for testing datasets) and boosted decision tress for permeability of pervious concrete (R2 = 0.9323 for training datasets and R2 = 0.7574 for testing datasets). The sensitivity analysis of the random forest regression model reveals that ultrasonic pulse velocity is the most influential parameter for the prediction of porosity and permeability of pervious concrete. The proposed models provide a more accurate method for estimating the porosity and permeability of pervious concrete.

Sustainable pervious concrete incorporated with graphene oxide: a comprehensive analysis of mechanical, infiltration and microstructure performance

ABSTRACT This study is a novel coalescence of using laboratory-based self-synthesised Graphene Oxide (GO) in pervious concrete (PC). The study aims to determine the effect of GO on the workability, paste drain down, porosity using CT scanning, hardened density, mechanical, infiltration and microstructural properties of previous concrete. Six mixes were designed with GO incorporation by cement weight (0, 0.02, 0.04, 0.06, 0.08 and 0.1 wt%). At 0.1 wt% of GO, the compressive strength of PC was 31.03 and 32.89 MPa at 28 and 56 days, respectively. Regarding splitting tensile strength, values were 3.68 and 3.9 MPa, and shear strength measured 4.88 and 5.12 MPa for the corresponding periods. Significant increment of 52.1% and 57% in compressive strength was observed at 28 and 56 days. The infiltration rate of all the mixes has shown a declining trend with an increase in GO percentage, and the maximum decrement was observed in the mix containing 0.1% of GO with 11.67% reduction of infiltration compared to control PC, but was within the standard permeable range as per American Concrete Institute (ACI 522R-10). Microstructural analysis revealed improved GO-modified PC performance, enhancing mechanical strength and infiltration characteristics, offering a promising and innovative solution for sustainable pavement development.

Performance Analysis of Ferronickel Slag-Ordinary Portland Cement Pervious Concrete.

It is unknown whether Ferronickel slag (FNS)-ordinary Portland cement (OPC)-based pervious concrete (FOPC) is feasible. To this end, a feasibility study was conducted on FOPC. Firstly, a detailed microscopic examination of the FNS powder was conducted, encompassing analyses of its particle size distribution, SEM, EDS, and chemical composition. These analyses aimed to establish the suitability of a composite of FNS and OPC as a composite cementitious material. Subsequent experimentation focused on evaluating the compressive strength of the composite paste material with varying mixed proportions, revealing a slight reduction in strength as the FNS substitution rate increased. Furthermore, the study designed eighteen different mix proportions of FOPC to investigate the key physical properties, including porosity, density, compressive strength, and the coefficient of permeability. Findings indicated that increases in the cementitious material proportion correlate with enhanced concrete strength, where the ratio of cementitious to aggregate increased by 6.7% and 16.5%, and the strength of FOPC increased by 10-13% and 30-50%, respectively. Conversely, a rise in the FNS substitution rate led to a reduction in compressive strength across different mix ratios. Additionally, the ratio of paste material to aggregate was found to significantly influence the permeability coefficient. These comprehensive performance evaluations suggest that incorporating FNS into OPC for pervious concrete applications is a feasible approach, offering valuable insights for the promotion of waste reuse and the advancement of energy conservation and emissions reduction efforts.

Corrosion of Steel Rebars in Construction Materials with Reinforced Pervious Concrete

Pervious concrete has great potential for use in many practical applications as a part of urban facilities that can add value through water harvesting and mitigating severe damage from floods. The construction and agricultural industries can take direct advantage of pervious concrete’s characteristics when water is a key factor included in projects as part of the useful life of a facility. Pervious concrete also has applications in vertical constructions, fountains, and pedestrian crossings. This work evidences that pervious concrete’s corrosion current increases with increasing aggregate size. Also, corrosion is a factor to consider only when steel pieces are immersed, aggravated by the presence of chlorine, but it drains water and does not retain moisture. Steel-reinforced pervious concrete was studied, and the grain size of the inert material and the corrosion process parameters were investigated. The electrochemical frequency modulation technique is proposed as a suitable test for a fast, reproducible assessment which, without damaging reinforced cement structures, particularly pervious concrete, indicates a trend of increasing corrosion current density as the size of the aggregate increases or density diminishes.

Pressure drop and heat transfer properties for normal weight and lightweight pervious concrete

This study examines the performance of pervious concrete when used for heating and cooling through forced air conditions. The influence of aggregate type, water-cement ratio, and paste volume on the air flow characteristics were examined through experimental evaluation of 10 mixes. The thermal properties and sensible heat energy stored in the pervious concrete were evaluated by measuring temperature changes with hot air flow. The results show that at a velocity of 0.35 m/s, the pressure drop falls within the range of 500 Pa/m to 8000 Pa/m. The pressure drop increases with an increase in the volume of paste to volume of aggregate ratio and decreases in water/cement ratio due to changes in the porosity and interconnected void structure of the pervious concrete. A modified pressure drop formulation based on the porosity, volume of paste to aggregate, and water/cement ratio is developed which provides a reasonable prediction for pervious concrete. The energy stored in the concrete can be accurately estimated based on the measured specific heat of the pervious concrete.

High strength rubberized porous concrete for sustainable pavements: Engineering properties and life cycle assessment

This study investigates the performance of Pervious Concrete (PC) with varying quantities of Natural Coarse Aggregate (NCA) replaced by Waste Tire Rubber (WTR) (5%, 10% and 15% by weight) whereas Silica Fume (SF) (5%, 10% and 15%) and Fly Ash (FA) (10% constant) were employed as substitute for cement. This research aims at optimizing the mix of High Strength Rubberized Pervious Concrete (HSRPC) using Supplementary Cementitious Materials (SCMs), comparing experimental stress-strain graphs with the developed constitutive models and conducting a Life Cycle Assessment (LCA). Physical and mechanical performance of PC were examined using permeability and strength indices. X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) observed microstructural variations and Interfacial Transition Zone (ITZ) development. The use of WTR increased the permeability and decreased the strength indices. The permeability of mixes with 5, 10 and 15% WTR was found to be 4.00, 4.21 and 4.49 mm/s, which were more than control mix permeability. The compressive strength of PC with 5%, 10%, and 15% WTR was determined to be 32.48, 29.29, and 26.94 MPa, respectively, which were lower than control PC compressive strength which was 35.41 MPa. However, the addition of SF and FA enhanced the mechanical properties while causing a decrease in the permeability. Increasing SF content from 0% to 15% enhanced the compressive strength of PC containing 5% WTR, from 32.48 to 40.71 MPa. Developed constitutive models compared the stress-strain response of PC. Life cycle assessment showed that WTR, SF, and FA-based PC reduced the global warming.

Experimental Study of Interface Shear Characteristics of Pervious Concrete and Carbonated Soil in the MgO-Carbonated Composite Pile

Experimental Study of Interface Shear Characteristics of Pervious Concrete and Carbonated Soil in the MgO-Carbonated Composite Pile

Closure to “Effect of Underreamed Pervious Concrete Columns on Load-Carrying Capacity of Loose Cohesionless Soils”

Closure to “Effect of Underreamed Pervious Concrete Columns on Load-Carrying Capacity of Loose Cohesionless Soils”

Development of Pervious Concrete with Enhanced Skid Resistance using Waste Tires Particles

Rubber tires are excessively increasing with the advancement in transportation technologies. It is difficult to dispose off the tires and as such they cause environmental threats to the on-land and aquatic lives. In this work crumb rubber is used as a fractional replacement of sand in concrete at 5%, 10% and 15% by mass. The aim is to produce a porous concrete with acceptable mechanical strength and high skid resistance. The workability and fresh density of the concrete decreased with the crumb rubber. Similar reduction in mechanical strength was also noticed, however, 5% replacement showed mechanical properties similar to those of the control units. The crumb rubber enhanced the porosity of the material. The study as a whole suggests that a lightweight concrete with enhanced porosity and skid resistance can be produced by recycling crumb rubber as a partial replacement of sand. The porous concrete with good skid resistance is a useful pavement material as it allows the infiltration of rainwater through it and thus has the capacity to reduce runoff during heavy rainfalls. It can additionally help reduce the accidents due to higher skid resistance in wet conditions.

Variation of aggregate size using sensors based on impact strength of pervious concrete

Pervious concrete is a high porosity concrete and this focussed on the effect of coarse aggregate size on the mechanical and impact strength of pervious concrete. Compressive and split tensile strengths are considered for mechanical properties. Porosity as hydraulic and impact strengths were evaluated. The coarse aggregate used in this was grouped in three categories based on the size of M1, M2, and M3 with 16 mm, 12 mm, and 10 mm respectively. Fly ash as secondary cementitious material replaced cement from 0 to 30%, and a total of twenty-one mixes were considered using sensorsfor this study. The various mineral phases available in the concrete was identified with XRD analysis. The results concluded that the M3 mix with 20% FA enhanced the mechanical properties and lower in impact strength. M1 mix with 20% FA can be a sustainable pervious concrete mix.

Pervious Concrete and Pervious Mortar as Water Filter in Decentralized Water Treatment– a Review

Decentralized water treatment system is water treatment carried out by the community on a household-scale. One of the technologies that have been developed to gain freshwater is the pervious concrete filter (PCF). This study aims to provide the researchers with an understanding of the pervious concrete filter as a potential filter technology in water treatment. The method used is a literature review from several papers and reports related to pervious concrete from past to present. PCF is a filter made from a mixture of aggregate, cement, and water with a specific ratio. PCF has enough water and air permeability due to interconnected macro pores. Some properties such as porosity, permeability, and pores size determine the ability of PCF to remove the contaminants in the water. These properties were controlled mostly by the aggregate size, aggregate-cement ratio, water-cement ratio, etc. According to its characteristic, the PCF shows a prospect to be used as water filter mainly in a decentralized water treatment system. Besides, the understanding of PCF is a basis to develop a pervious mortar filter that slightly different in the aggregate sizes used in this composite.

The Prediction of Pervious Concrete Compressive Strength Based on a Convolutional Neural Network

To overcome limitations inherent in existing mechanical performance prediction models for pervious concrete, including material constraints, limited applicability, and inadequate accuracy, this study employs a deep learning approach to construct a Convolutional Neural Network (CNN) model with three convolutional modules. The primary objective of the model is to precisely predict the 28-day compressive strength of pervious concrete. Eight input variables, encompassing coarse and fine aggregate content, water content, admixture content, cement content, fly ash content, and silica fume content, were selected for the model. The dataset utilized for both model training and testing consists of 111 sample sets. To ensure the model’s coverage within the practical range of pervious concrete strength and to enhance its robustness in real-world applications, an additional 12 sets of experimental data were incorporated for training and testing. The research findings indicate that, in comparison to the conventional machine learning method of Backpropagation (BP) neural networks, the developed CNN prediction model in this paper demonstrates a higher coefficient of determination, reaching 0.938, on the test dataset. The mean absolute percentage error is 9.13%, signifying that the proposed prediction model exhibits notable accuracy and universality in predicting the 28-day compressive strength of pervious concrete, regardless of the materials used in its preparation.

Microscopic Factors Affecting the Performance of Pervious Concrete.

The impacts of various aggregate particle sizes and cement contents on the internal structure of pervious concrete were investigated. Accordingly, test blocks with different aggregate particle sizes and cement contents were dissected and photographed. Subsequently, the captured images were processed using the ImageJ software (1.53i) to analyze the profiles of the test blocks and identify the internal mesoscopic parameters of the pervious concrete. This study discusses the relationship between microscopic parameters and macroscopic factors based on experimental results. It also fits functional equations linking the permeability coefficient with pore parameters, matrix parameters, and compressive strength. The results indicated that, as the aggregate size increased, the internal pore diameter of the pervious concrete increased, whereas the total area and width of the cement matrix decreased. This resulted in a low permeability coefficient and high compressive strength of the test block. Increasing the cement content in pervious concrete reduced the porosity and increased the width and area of the internal matrix. Consequently, the permeability coefficient decreased, and the compressive strength of the test block increased.

Influence of Self-Compound Enhancer on Physical Properties of Pervious Concrete

The new enhancer was a self-compound enhancer (SCE) made of silica fume, potassium lignosulfonate and sodium silicate. The performance of the mixed enhancer was analyzed in depth by X-ray diffraction spectrum analysis (XRD) and infrared spectroscopy (FTIR) techniques to determine the feasibility of SCE. The new pervious concretes (PCs) were prepared using Portland cement as a binder, gravel and c-brass aggregates as the coarse aggregates and SCE as a new enhancer. A series of laboratory experiments were carried out to study the influence of the different amounts of SCE on the compressive strength, water permeability coefficient and microstructure of cement hydration products of high-strength and high-permeability pervious concrete (HHPC). When the amount of SCE reached 3.8–4.0%, a maximum of the compressive strength of HHPC reached 31.33 MPa, and a maximum of the water permeability coefficient of HHPC reached 2.48 mm/s. At this time, a dense and solid network C-S-H was formed in the cement slurry, and the momentum of C-S-H divergence at the junction was very strong. The test results show that when SCE is used as a new enhancer, HHPC can form a perfect skeleton-void structure, which not only meets the engineering strength requirements, but also meets the requirements of eco-friendly water permeability and permeability. It is an environment-friendly concrete.

Correlations among physical properties of pervious concrete with different aggregate sizes and mix proportions

Permeable pavement material can benefit urban environment. Here in this work, different aggregate sizes and mix proportions were used to manufacture pervious pavement concrete and investigate correlations among its properties. The porosity, permeability, compressive strength, inner structure, thermal conductivity, and abrasion resistance of the specimens were obtained. Results showed lower aggregate-to-cement ratios and higher water-to-cement ratios led to porosity reduction, which decreased the permeability coefficient but increased the compressive strength, thermal conductivity, and abrasion resistance of the pervious concrete. Compared to the mixes, the aggregate sizes affected the physical properties of pervious concrete less. However, the sizes of pores and cement in the pervious concrete were more affected by aggregate sizes than by mixes. Moreover, the porosity, permeability coefficient, and compressive strength of the pervious concrete can be correlated by the power law, whereas the correlation between the porosity and abrasion resistance index can be fitted by a linear law.

EXPERIMENTAL INVESTIGATION AND INTELLIGENT PREDICTION OF MECHANICAL STRENGTH OF PERVIOUS CONCRETE

This study determines the mechanical strength characteristics of pervious concrete using fuzzy logic. During construction, the process of determining the quality of concrete produced takes about 28 days before testing, training the fuzzy logic model through the research data gotten from the laboratory experiments in order to intelligently predict the mechanical strength of pervious concrete. Crushed granite was used in this experiment to ensure the pervious concrete has a little degree of fine aggregates and the maximum size of coarse aggregate used was 20 mm. Compressive, flexural and split tensile strength tests were carried out on pervious concrete of mixing ratios 1:4, 1:5 and 1:6 with each of the mixing ratios having varying water to cement ratios of 0.4, 0.5, 0.6 and 0.7. The developed fuzzy logic model was applied to predict the mechanical strengths of the concrete by using data obtained from experimental results, with input parameters of water content, crushing value, weight and density and the mechanical strengths as the output parameters employing the triangular membership function. The model was calibrated using the error measures of the root mean square error (RMSE), mean absolute percentage error (MAPE) and R squared were computed for the model. In this study, it was observed that higher water to cement ratio slightly reduces the mechanical strength of PC but increases the workability compared to increase in cement to granite ratio which notably increases the strength and reduced the workability, alternatively, higher water to cement ratio causes a notable decrease in permeability of the pervious concrete. The correlation between the experimental and predicted values was excellent. This shows that fuzzy logic can be used to predict the mechanical properties of pervious concrete, and fuzzy logic can also be used to appropriately deduce missing values in the mechanical properties of PC subject to further research

Effect of carbonation on development of reactive MgO-based pervious concrete

Pervious concrete, developed to solve urban flooding and overloaded drainage issues, has limited strength due to its large void ratio. Reactive MgO cement (RMC) is a sustainable cement gaining strength through carbonation, which can have a more pronounced carbonation-induced enhancement in mechanical properties compared with Portland cement. However, its carbonation degree was limited due to the dense microstructure. To address both issues, pervious concrete using RMC was developed, and its void ratios were leveraged to facilitate the carbonation of RMC. Experimental results revealed that compared with that of samples cured under ambient environment (i.e. 4.7–15.7 MPa), the compressive strength of RMC-based pervious concrete cured under accelerated carbonation (11.2–39.7 MPa) and water/CO2 cycles (10.3–29.6 MPa) was enhanced by 77–278%. As the design void ratio increased from 0.15 to 0.30, the permeability coefficient of pervious concrete increased from 0.1 to 2.3 mm/s, while the carbonation of RMC-based pervious concrete also benefited from high void ratio, with the highest 28-day carbon sequestration ratio reaching 12.7%, as indicated by XRD, TGA tests and SEM observations. Furthermore, a mathematical model was established to estimate the thickness of cement paste on aggregates in pervious concrete, which was less than 1 mm and decreased as the design void ratio increased.

Numerical modelling on coupled behavior of calcium leaching and chloride transport in cement-based materials by considering ion desorption

Concrete structures serving in water environment with rich chloride ions are subjected to the coupling action of calcium leaching and chloride corrosion. In this paper, a transport model of calcium and chloride ions coupled with the calcium solid-liquid equilibrium equation is proposed to simulate the behavior of calcium leaching and chloride penetration in concrete. In the model, the effect of free chloride ions bound by solid calcium and the release of bound chloride ions caused by the dissolution of solid calcium is considered. Secondly, the model is numerically solved by using the finite difference method of Crank-Nicolson scheme. Then, the experimental data of porosity and calcium silicon ratio, chloride concentration are compared to the calculated results to validate the model. Finally, a numerical simulation is conducted to analyze the evolution of ion concentration, solid calcium content and porosity of cement paste slice exposed to deionized water and accelerated dissolution solution. The results show that, the concentration of calcium ion decreases with corrosion time, while that of chloride ion increases. There are concentration gradient distributions of calcium and chloride ions in the slice. The higher the concentration of accelerated dissolution solution, the larger the porosity of cement paste and the higher the concentration of chloride ions in the paste. It indicates that, the calcium leaching accelerates the chloride penetration into concrete. In addition, the dissolution process of solid calcium, i.e. calcium hydroxide first dissolves followed by C-S-H gel, are presented.