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Solid waste materials (SWM) are commonly used in the preparation of building materials due to their structural characteristics and chemical composition. Pervious concrete (PC) is a green infrastructure material that offers advantages such as reducing surface runoff and purifying water quality, making it an important component of sponge cities. This study aims to investigate the physical properties and micro-structure of PC prepared from various SWM and determine the optimal mix proportion. In this study, three common SWM, including muck, steel slag (SS) and fly ash (FA), are used as raw materials. The chemical composition and physical properties of SWM are analyzed. A five-level and five-factor test scheme is developed using the orthogonal test method. This scheme considers the target porosity, water–cement ratio, muck content, SS content, and FA content as variables. The mechanical properties and permeability of PC, including compressive strength, porosity and permeability coefficient are evaluated. The internal structure of PC is observed using a scanning electron microscope (SEM). The results indicate that the optimal mix proportion for preparing PC is determined through efficiency coefficient method analysis: target porosity of 25%, water–cement ratio of 0.36, muck content of 10%, SS content of 10%, and FA content of 12.5%. The corresponding performance indicators of the PC sample are measured as follows: porosity of 24.67%, compressive strength of 15.78 MPa, and permeability coefficient of 2.23 mm/s. This study provides valuable insights for the rapid and flexible batching and performance optimization research of PC based on SWM. [ABSTRACT FROM AUTHOR]

The present study investigates the effect of the total amount of chemical constituents in cement and supplementary cementitious materials on the compressive strength of pervious concrete. Experimental datasets were collected from the literature on different types of pervious concrete specimens modified with supplementary cementitious materials. A total of 659 data observations were collected. These were then analysed and modelled using three different approaches: linear regression (LR), full quadratic (FQ) and artificial neural network (ANN) models. These models' purpose was to predict pervious concrete's compressive strength. The accuracy of the models was evaluated using correlation coefficient (R2), root mean square error (RMSE), mean absolute error (MAE), a-20 index and error distribution. The ANN model demonstrated superior effectiveness and accuracy in predicting the compressive strength of pervious concrete, as indicated by the performance metrics. The analysis results showed that Al2O3 content and curing time were the most influential parameters in predicting the compressive strength of concrete. In addition, SHapley Additive exPlanations (SHAP) analysis could determine if each input variable had a positive or negative effect on compressive strength. Al2O3, CaO, curing time and water content positively affected the compressive strength of pervious concrete, while SiO2 and corresponding alkalis had a negative effect. [ABSTRACT FROM AUTHOR]

The major objective of this research was to develop an innovative approach to characterise the pore structure of pervious concrete (PC) mixtures and quantify tortuosity in pre- and post-clogged conditions through 2D and 3D image analysis. Four different types of PC mixtures were prepared and subjected to computed tomography (CT) scanning to retrieve morphological information covering over 1900 images, followed by tortuosity quantification of each of 200 interconnected pore paths using vascular modelling toolkit (VMTK). The porosity of PC obtained from laboratory-based tests was 10–25% lower than image analyses. Further, along the depth of PC, a significant decrease in the number of pores in the top 60–80 mm was observed due to clogging, which revealed that maintenance be adopted only in the top 80 mm. Control and clogged PC with smaller sized aggregates and lower w/c ratio were more tortuous compared to higher w/c ratio while opposite for larger sized aggregates, ascribed to the occurrence of shorter interconnected pore paths comprising larger pore diameter, remarking that permeability will depend on both tortuosity and path diameter. CT scanning was used in predicting tortuosity and pore interconnectivity of PC through VMTK approach extensively used in medical science and seldom used in engineering. [ABSTRACT FROM AUTHOR]

Pervious concrete is proven to environmentally benefit urban pavement construction. Optimising compaction energy evidently reduces uncertainty in the mass production of pervious concrete with uniform characteristics. The distribution of compaction energy in wet mix and rearrangement of binder-coated aggregate particles are affected by the size and shape of aggregates. This study analyses the impact of aggregate size and shape on porosity and compressive strength prediction from mix-design parameters. Aggregate-to-cement ratio (3, 4 and 5), compaction (0, 30 and 60 blows from standard Proctor rammer), aggregate sizes (5–12 mm, 12–18 mm and 18–25 mm) and aggregate shape (0, 200 and 1000 revolutions of milling in Los Angeles Abrasion Value) were used to cast a total number of 486 samples. Constituents were mixed in an electrically powered drum of capacity 96 L, for 20 min. Porosity was computed from constituent ratios (theoretical porosity) and apparent weight (measured porosity). The compressive strength of samples was recorded using a Universal Testing Machine. The measured porosity and theoretical porosity relationship was significantly affected by the shape of the aggregate and not by the size. Modified Ryshkewitch's model predicted compressive strength from porosity, aggregate-to-cement ratio, compaction and aggregate size and shape with an accuracy of 0.92 (R2). Two of six arbitrary constants depended on aggregate shape and size. [ABSTRACT FROM AUTHOR]

The porosity and compressive strength of pervious concrete are critical determinants of its suitability for various applications. Therefore, it is necessary to recognise the factors influencing the performance and its ranks to balance porosity and compressive strength ideally. This study evaluates the impact of aggregate shape, size, aggregate-to-cement ratio and compaction effort on previous concrete performance. The research involved varying aggregate sizes (5–12 mm, 12–18 mm and 18–25 mm), aggregate-to-cement ratios (3.0, 4.0 and 5.0), compaction efforts (0, 30 and 60 blows) and aggregates underwent revolutions in a ball mill (0, 200 and 1000) to change their morphological characteristics. A total of 81 mix designs were tested, resulting in 486 cubes for compressive strength and porosity testing. The acquired data underwent analysis using the statistical analysis and Taguchi method to discern the most influential factors and establish their ranking. The results indicate that revolutions, compaction, aggregate-to-cement ratio and aggregate size contribute 29.42%, 26.19%, 29.13% and 0.96%, respectively, to the compressive strength performance. Regarding porosity performance, revolutions and compaction emerge as significant factors, accounting for 39.95% and 26.91%, respectively. The influence of the aggregate-to-cement ratio and aggregate size on porosity performance appears less pronounced. [ABSTRACT FROM AUTHOR]

Pavements create an impermeable layer, contributing to a decrease in groundwater recharge and a rise in flood frequency in urban areas. Pervious concrete pavement (PCP) is considered one of the solutions to address the problems associated with impermeability. Due to the low-strength applications of PCP and to address the environmental issues associated with recycled concrete aggregate (RCA) and recycled asphalt pavement (RAP), studies have used them as replacements for natural aggregate (NA). Past studies recommended the optimum RCA or RAP content based on mechanical and durability investigations. This study investigates strength and environmental aspects of using RCA and RAP in PC by replacing NA with RCA and RAP at 30, 60, and 90% by volume. The compressive strength of RCA-PC mixtures at 7 days was found to be higher than that of RAP-PC mixtures, while RAP-PC mixtures displayed better abrasion resistance. Total embodied energy (TEE) and greenhouse gas emissions (GHG) with 90% replacement of RCA and RAP were 6.5–7.5% and 12.5–13.42% lower than control mixtures for different transportation distances, respectively. The cost-per-strength ratio indicated that RCA-PC mixtures were more preferred than RAP-PC mixtures. Overall, the study recommends 30% RCA/RAP content in PC, considering strength, cost, and environmental aspects. [ABSTRACT FROM AUTHOR]

Large porosity and interconnected pore structure allow pervious concrete to find interesting applications in urban pavement. At the same time, accounting for the exorbitant greenhouse gas emissions associated with Portland cement production, the application of supplementary cementitious materials (SCMs) in pervious concrete has received significant attention in studies. This research investigates the feasibility of developing pervious concrete by substituting a high volume of Portland cement with slag. Different mixtures were made to investigate the effects of high-volume slag content (60% and 80%), fine aggregate incorporation (10% and 15%) and combined use of SCMs (high-volume slag + silica fume) in pervious concrete. Concretes were tested for void content, compressive strength, permeability and abrasion resistance. Based on the results, although the compressive strength of pervious concrete was decreased by the inclusion of high-volume slag, it can be compensated to some extent by increasing the curing age. Furthermore, by decreasing the material cost and CO2 emissions up to 8.2% and 61.2% over plain pervious concrete, respectively, utilisation of high-volume slag can produce relatively more cost-effective and eco-friendly pervious concrete. In general, combined use of slag + silica fume or incorporation of fine aggregate at the optimum replacement ratio can be suggested to obtain higher strength and acceptable permeability in high-volume slag pervious concrete. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In order to solve the problem that pervious concrete used in northern coastal cities is susceptible to seawater-freeze-thaw co-action in winter, orthogonal tests were used to investigate the effects of slag (GBFS) substitution rate, hydroxypropylmethylcellulose (HPMC) admixture, and polypropylene imitation steel fiber (PPTF) admixture on macroscopic properties and microstructural changes of the pervious concrete blocks after seawater-freeze-thaw co-action for 25, 50, and 75 times, and the NSGM(1,N) model was used to predict the relative dynamic elastic modulus of pervious concrete after seawater-freeze-thaw co-action. The NSGM(1,N) model was applied to predict the relative dynamic elastic modulus of permeable concrete after seawater-freeze-thaw. The results show that the permeable concrete has the best seawater-freeze-thaw resistance when the GBFS substitution ratess 20% and the HPMC and PPTF admixture are 0.15% and 0.5%, respectively; after seawater erosion, the generation of expansive substances accelerated the crack extension, and the supportive anchoring effect of PPTF suppressed the crack generation and extension. The test index a of the prediction accuracy of the NSGM(1,N) model is in [-3,2), and the average relative error is within the range of grade II error. The NSGM(1,N) model can be used for long-term prediction of the relative dynamic elastic modulus. [ABSTRACT FROM AUTHOR]

Conventional impervious pavements occupy a large proportion of most cities, due to urbanization and the extensive development of transportation infrastructure. These pavements cause environmental problems such as flooding and urban heat islands. Pervious concrete (PC) is a special type of concrete, characterized by a porous structure that allows water infiltration and has the potential to reduce the effects of urban heat islands through cooling by evaporation. However, due to the low water absorption and retention properties of PC, it cannot effectively meet evaporative cooling needs. This study investigates the thermal behavior of PC in dry and wet laboratory conditions under controlled climatic conditions. Three types of PCs were fabricated: gravel-based PC (PCG) and Pozzolan-based PC (PCP1), having almost the same particle size distribution, and less coarse Pozzolan-based PC with a monodisperse particle size distribution (PCP2). The results show that the surface temperature of pozzolan-based PC is up to 4 °C higher than that of PCG in dry conditions. The partial immersion test shows that the use of pozzolan aggregates in PC mixtures improves the water-absorption properties compared to PCG. In addition, pozzolan-based PC can have a surface temperature up to 11.7 °C lower than PCG during the daytime and up to 3 °C lower during the nighttime. The use of lightweight aggregates with high water-absorption coefficients in the PC mix is only recommended in wet conditions. [ABSTRACT FROM AUTHOR]

This study investigated the purification of pollutants in runoff rainwater by constructing a micro-ecosystem using waste-activated sludge (WAS) and riverbed sludge (RBS) as inoculums in combination with pervious concrete. The research results showed that the best hydraulic retention time (HRT) was 9 h. The COD and ammonia nitrogen (NH4+-N) removal of the waste-activated sludge ecosystem (WASE) was 62.67% and 71.21%, respectively, while the riverbed sludge ecosystem (RBSE) showed COD and NH4+-N removal percentages of 46.05% and 66.55%, respectively. The analysis of the genetic metabolism of microbial genes showed that the system was microbially enhanced with extensive and diverse populations. At the phylum level, the microorganisms responsible for degrading organic matter were mainly Firmicutes and Actinobacteriota. At the genus level, the Trichococcus genus was dominant in the WASE, while the Dietzia, norank_f__Sporomusaceae and norank_f__norank_o__norank_c__BRH-c20a genera were the central bacterial populations in the RBSE. The proliferation of phylum-level bacteria in the WASE was relatively large, and the genus-level bacteria demonstrated a better removal efficiency for pollutants. The overall removal effect of the WASE was better than that of the RBSE. The application analyses showed that a WASE is capable of effectively accepting and treating all rainfall below rainstorm levels and at near-full rainstorm levels under optimal removal efficiency conditions. This study innovatively used wastewater plant waste-activated sludge combined with pervious concrete to construct a micro-ecosystem to remove runoff rainwater pollutants. The system achieved pollutant removal comparable to that of pervious concrete modified with adsorbent materials. An effective method for the collection and pollutant treatment of urban runoff rainwater is provided. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering (17264073) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Stormwater runoffs cause adverse impacts on groundwater quality and imperil the sustainable development of human society. Porous pavement can be considered as the first line of defense for contaminant removal from stormwater runoff. The main aim of this study is to produce green porous concrete with improved treatment ability and justified mechanical and hydraulic properties. The physical and mechanical properties, as well as the runoff purification characteristics of environmentally friendly water-permeable concrete using recycled concrete, ceramics, and pumice aggregates, were investigated to present the effective utilization of recycled materials and approach a methodology to enhance the purification of porous concrete. Results demonstrated that the porous concrete incorporating recycled aggregates had promising physical and mechanical properties. Pumice replacement led to an increase in void content, and water adsorption, while a decrease in hardened density was noted. The mechanical properties were adversely affected due to the weak recycled aggregates and aggregate-mortar interface. Moreover, the results demonstrate that the sample containing 25% pumice aggregate had the highest removal efficiency of TSS, TN, NO3-N, TP, COD, NH4-N by 77.43, 48.43, 55.26, 85.48, 51.63, 42.22%, respectively. However, 25% replacement of pumice aggregate decreased the compressive strength to 30% compared to the specimen without pumice aggregates. This research presents a novel concrete mix in terms of balancing treatment capacity and mechanical properties. Experimental findings highlight the ability to use porous concrete containing recycled aggregates with enhanced purifying characteristics in pavement applications. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Copyright of Transportation Science & Technolgy is the property of Transportation Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study investigates the performance of sludge-added pervious concrete (SPC) at different curing temperatures by replacing some of the cement with activated sludge (AS). The results reveal that the incorporation of AS into pervious concrete had a favorable impact. At a curing temperature of 30 °C, the 28-day compressive strength and specific surface area reached 20.8 MPa and 9.14 m2/g, respectively, representing a 60% and 98.7% increase, in comparison to conventional concrete. Furthermore, the addition of AS to the concrete results in a notable reduction in the concentration of chemical oxygen demand (COD) in surface runoff water. The maximum rate of COD removal observed was 55.6%. A mechanism study revealed that the strength of concrete increased due to the reaction between reactive SiO2 in AS and CaO in the aggregate. At a temperature of 30 °C, the microorganisms in the activated sludge fermentation process exhibit a higher production rate of fermentation gas, resulting in a greater escape of gas and an increase in the number of micropores in the permeable concrete. This leads to an enhanced specific surface area, which in turn exhibits a superior adsorption effect on COD. [ABSTRACT FROM AUTHOR]

The construction demolition is non-degradable. Recycled aggregates were utilized to create sustainable products in pervious concrete manufacture. Adding fibers enhances pervious concrete mechanical properties. High absorption of Recycled aggregate (RA) and polyethylene-glycol are used to ensure internal curing. The purpose of this study was to statistically improve the mechanical properties of pervious concrete based on an experimental investigation. Taguchi method was employed to present DOE (Design of Experiment). Five factors in four levels designed by Taguchi provide sixteen mixes (L16 array). The factors were the replacement of coarse aggregates by recycled aggregates, W/C ratio, synthetic macro-fiber, steel fiber and polyethylene-glycol. Designed mixes were prepared. Taguchi's analysis concluded; that macro-fiber addition has no impact on mechanical properties. Using a ratio of 10% recycled aggregates replacement was the optimum ratio. Taguchi prediction of optimum mixes was experimented with using mixes. Confirmation test results agree with the predicted values within ±10%. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the physical, mechanical, permeability, and durability characteristics of pervious geopolymer concrete (PGC) made with recycled concrete aggregates (RCA), blast furnace slag (GGBS), and fly ash (FA). PGC mixes were formulated to attain two design porosities, 10 and 15%, using two binder combinations of GGBS:FA at ratios of 1:0 and 1:1. Natural coarse aggregates (NCA) were substituted with up to 100% RCA. Hardened density, porosity, compressive, splitting tensile, and flexural strengths, permeability, and abrasion resistance were determined. Results showed that PGC mixes had superior or comparable performance to the control mix made with cement and NCA. The incorporation of RCA or FA into the PGC mix reduced the hardened density, strengths, and abrasion resistance, while increasing porosity and permeability. The combined effect of FA inclusion and higher design porosity of 15% intensified the reduction in performance. The clogging and permeability restoration potential were evaluated after a simulated 20-year exposure to clogging materials. Despite permeability losses reaching 71% due to clogging, nearly 94% of the initial permeability could be restored through pressurised water washing. Research findings highlight the ability to valorise GGBS, FA, and RCA in the production of a cement-free PGC for use in pavement applications. [ABSTRACT FROM AUTHOR]

Increasing of plastic waste threatening ecosystems globally, this experimental work investigates recycled plastics as sustainable aggregate replacements in pervious concrete. Pervious concrete allows water passage but has installation/maintenance difficulty due to high weight. This research addresses the lack of eco-friendly lightweight pervious solutions by assessing physical and mechanical performance of mixes with 100% recycled plastic and traditional aggregate percentages. Density reduced 12% using a 100% plastic aggregate mix, achieving 1358 kg/m3 with compressive strength of 3.92 MPa, adequate for non-structural applications. A 7.8% decrease in water absorption versus conventional pervious concrete signifies retained porosity and permeability despite the plastic aggregates. Though early material limitations increase costs over 199.32%, recycled plastics show viability as effective, sustainable substitutes for natural aggregates in lightweight pervious concrete. With further availability and affordability improvements, these recyclable mixes can enable significantly greener construction practices. Findings provide key insights on balancing structural requirements, eco-friendliness and water infiltration capacity in plastic-based lightweight pervious concrete for broader adoption. The research examines the mechanical and durability characteristics of Light-Weight Pervious Concrete (LWPC) composed entirely of plastic aggregate. It also investigates the economic viability and potential for sustainable urban applications. The cost assessment reveals long-term environmental advantages, even though the initial expenses are higher. Additionally, the study considers an eco-friendly approach that combines plant growth with pervious concrete to promote greater sustainability. [ABSTRACT FROM AUTHOR]

This paper studies the potential of using municipal solid waste incineration bottom ash (MSWI-BA) to produce an eco-friendly pervious concrete pavement in Lebanon, reduce landfill demand, and decrease the requirement of natural resources. The performance of a pervious concrete containing different contents of MSWI-BA, obtained from a plant in Lebanon, as a partial replacement of natural aggregate (NA) was investigated. The first stage of the research was to select appropriate mix proportions to produce pervious concrete with relatively high permeability and high strength with coarse natural aggregate particle size ranging from 2.36 to 9.5 mm. A control mix (M1) was chosen without the use of MSWI-BA. In the other mixes, the natural aggregate was replaced with 25%, 50%, 75%, and 100% MSWI-BA (by volume), having similar particle size. The effects of MSWI-BA replacement on the water permeability, compressive strength, flexural strength, ultrasonic pulse velocity (UPV), connected porosity, total porosity, and density were examined. The results demonstrated that even though there is a decrease in the permeability, strength, and connected porosity of pervious concrete, the engineering properties still meet the standard requirements for pervious concrete, indicating the possibility of producing an eco-friendly concrete with a total replacement of natural aggregate with 100% MSWI-BA. [ABSTRACT FROM AUTHOR]

Pervious concrete, because of its high porosity, is a suitable material for reducing the effects of water precipitations and is primarily utilized in road pavements. In this study, the effects of binder-to-aggregate (B/A) ratios, as well as mineral admixtures with and without polypropylene fibers (PPFs) (0.2% by volume), including fly ash (FA) or silica fume (SF) (10% by substitution of cement), on the mechanical properties and durability of pervious concrete were experimentally observed. The experimental campaign included the following tests: permeability, porosity, compressive strength, splitting tensile strength, and flexural strength tests. The durability performance was evaluated by observing freeze–thaw cycles and abrasion resistance after 28 d curing. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA-DTA), and scanning electron microscopy (SEM) combined with energy dispersive spectroscopy (EDS) were employed to investigate the phase composition and microstructure. The results revealed that, for an assigned B/A ratio identified as optimal, the incorporation of mineral admixtures and fibers mutually compensated for their respective negative effects, resulting in the effective enhancement of both mechanical/microstructural characteristics and durability properties. In general, pervious concrete developed with fly ash or silica fume achieved higher compressive strength (>35 MPA) and permeability of 4 mm/s, whereas the binary combination of fly ash or silica fume with 0.2% PPFs yielded a flexural strength greater than 6 MPA and a permeability of 6 mm/s. Silica fume-based pervious concrete exhibited excellent performance in terms of freeze–thaw (F-T) cycling and abrasion resistance, followed by fiber-reinforced pervious concrete, except fly ash-based pervious concrete. Microstructural analysis showed that the inclusion of fly ash or silica fume reduced the harmful capillary pores and refined the pore enlargement caused by PPFs in the cement interface matrix through micro-filling and a pozzolanic reaction, leading to improved mechanical and durability characteristics of pervious concrete. [ABSTRACT FROM AUTHOR]

Pervious concrete is widely used as a paving material. Pervious pavement is generally constructed by pouring fresh pervious concrete and compacting. However, it has some difficulties such as finishing and curing. In addition, the road has to be closed, until the pervious concrete gains enough strength. Pervious concrete block is a new material that can overcome these difficulties. In this study, the effect of compression force on the strength and infiltration rate of pervious concrete blocks has been investigated. The compaction process was different from traditional methods in this study, and was applied according to predesignated compression forces on fresh pervious concrete mixtures sensitively. Within the scope of the study, 36 different mixtures were produced by applying four different compression forces (25, 50, 75, and 100 kN) in three different sample thicknesses (60, 80, and 100 mm) with three different aggregate sizes (2–4, 4–8, and 8–16 mm). As a result, it was found that while the increase in the compression force increases the splitting tensile strength of pervious concrete blocks with 2–4 and 4–8 mm aggregate, it causes a decrease in the strength due to the aggregate crushing phenomenon in mixtures with 8–16 mm aggregate, 6 cm thick samples. In this study, it was seen that the expectation that the increase in compaction would always cause an increase in strength is not valid, contrary to the literature. The infiltration rate decreased as the compression force increased, as expected. It was determined that the new infiltration rate measurement method has been found effective. Considering the strength requirement in the TS 2824 EN 1338 standard, pervious concrete blocks produced with 4–8 mm aggregate, compressed with 75 kN force and having 80 mm thickness have been determined as the optimum block type. [ABSTRACT FROM AUTHOR]

In recent years, various aspects of research related to pervious concrete (PC) have progressed rapidly, and it is necessary to summarise and generalise the latest research results. This paper reviews and compares the raw materials of pervious concrete, examining elements such as porosity, permeability, mechanical properties, and durability. According to comparisons, we put forward an ideal aggregate model with Uneven Surface, which may reinforce the mechanical properties. By summarising the important issues of aggregate, particle size, water–cement ratio, additives and admixtures, mixing ratio design, mixing and moulding, and other factors that affect porosity, new design methods are proposed. A new effective stress model of pervious concrete based on continuous porosity and Terzaghi effective stress is developed which may fit the effective stress principle better. Finally, by summarising the research frontiers of pervious concrete, key issues that need to be addressed in future scientific research on pervious concrete are raised. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the physical, mechanical, permeability, and durability characteristics of pervious geopolymer concrete (PGC) made with recycled concrete aggregates (RCA), blast furnace slag (GGBS), and fly ash (FA). PGC mixes were formulated to attain two design porosities, 10 and 15%, using two binder combinations of GGBS:FA at ratios of 1:0 and 1:1. Natural coarse aggregates (NCA) were substituted with up to 100% RCA. Hardened density, porosity, compressive, splitting tensile, and flexural strengths, permeability, and abrasion resistance were determined. Results showed that PGC mixes had superior or comparable performance to the control mix made with cement and NCA. The incorporation of RCA or FA into the PGC mix reduced the hardened density, strengths, and abrasion resistance, while increasing porosity and permeability. The combined effect of FA inclusion and higher design porosity of 15% intensified the reduction in performance. The clogging and permeability restoration potential were evaluated after a simulated 20-year exposure to clogging materials. Despite permeability losses reaching 71% due to clogging, nearly 94% of the initial permeability could be restored through pressurised water washing. Research findings highlight the ability to valorise GGBS, FA, and RCA in the production of a cement-free PGC for use in pavement applications.

Abstract Increasing of plastic waste threatening ecosystems globally, this experimental work investigates recycled plastics as sustainable aggregate replacements in pervious concrete. Pervious concrete allows water passage but has installation/maintenance difficulty due to high weight. This research addresses the lack of eco-friendly lightweight pervious solutions by assessing physical and mechanical performance of mixes with 100% recycled plastic and traditional aggregate percentages. Density reduced 12% using a 100% plastic aggregate mix, achieving 1358 kg/m3 with compressive strength of 3.92 MPa, adequate for non-structural applications. A 7.8% decrease in water absorption versus conventional pervious concrete signifies retained porosity and permeability despite the plastic aggregates. Though early material limitations increase costs over 199.32%, recycled plastics show viability as effective, sustainable substitutes for natural aggregates in lightweight pervious concrete. With further availability and affordability improvements, these recyclable mixes can enable significantly greener construction practices. Findings provide key insights on balancing structural requirements, eco-friendliness and water infiltration capacity in plastic-based lightweight pervious concrete for broader adoption. The research examines the mechanical and durability characteristics of Light-Weight Pervious Concrete (LWPC) composed entirely of plastic aggregate. It also investigates the economic viability and potential for sustainable urban applications. The cost assessment reveals long-term environmental advantages, even though the initial expenses are higher. Additionally, the study considers an eco-friendly approach that combines plant growth with pervious concrete to promote greater sustainability.

Pervious concrete (PC), commonly used in urban pavement, is known for its high permeability, which contributes to mitigating the urban heat island effect. However, the low strength and durability of PC limit its use. The objective of this study is to improve mechanical properties and durability of PC by adding cellulose nanofibrils (CNFs). The results showed that CNFs significantly enhanced compressive strength, flexural strength, and salt frost resistance, with optimal performance at 0.15% CNF. At this concentration, compressive and flexural strengths increased by 26.5% and 25.8%, respectively, despite a slight reduction of 10.2% in permeability. CNFs also improved resistance to salt-induced freeze–thaw cycles, reducing spalling and maintaining a higher value of the dynamic modulus of elasticity, particularly at 0.1% and 0.15% dosages. Scanning electron microscope (SEM) analyses revealed that CNFs create a denser, more uniform network of hydrated products, enhancing microstructure and interfacial bonding. This study confirms that CNFs can significantly enhance the mechanical properties and durability of PC. [ABSTRACT FROM AUTHOR]

In modern civil engineering, precisely predicting the mechanical properties of waste-modified geopolymer concrete is a vital challenge. Machine learning (ML) offers a powerful tool for such predictive analysis. This article presents an experimental and python-based intelligent ML modeling study on a type of geopolymer (GP) pervious concretes developed using agro-industrial waste products. The slag-based composite mixes were developed with the varying dosages of agro-waste, i.e., sugarcane bagasse ash (0 to 20% by weight of slag) and construction and demolition waste in the form of recycled coarse aggregates (0 to 100% by weight of natural aggregates). The aqueous solution of liquid Na2SiO3 and NaOH pellets were used as an alkali activator solution. A total of 13 different mix proportion designs were developed, and for every individual sample mix, the results were obtained from laboratory tests. The ML analysis was carried out to compute the compressive strength by applying following models: Multiple Linear Regression, tuned Gradient Boost, AdaBoost, and XGBoost Regressions. Further, an ensemble technique that combines the predictions from multiple ML algorithms together to make more accurate predictions than any individual model was also developed for a more accurate and robust prediction through the “Voting Regressor” technique. From the analysis of the obtained results, the ML models associated with Ada Boost tuned performed better. As the ensemble voting regressor models were given higher weightage, these regressors gave the best performance metrics, with lower error rate compared to the independent models.

This study investigates the effects of polycarboxylate-lignosulfonate superplasticizer (PLS), water, and cement content on mechanical, physical and cementitious paste thickness of pervious concrete (PC) for its further application in urban areas. For this reason, 17 PC mixtures containing different portions of PLS (0.10% to 1.00% of the cement content), water-to-cement ratio (0.30 to 0.40), and cement content (315 to 350 kg/m3) with a constant range aggregate size (4.75 to 9.5 mm) were designed, tested, and analyzed by Design of Expert (DoE). The results showed that increasing the proportion of PLS, water, and cement increased the compressive strength of PC at ages of 7, 11, and 28 days. However, the permeability and porosity would decrease due to formation of a pasty mixture. The effect of water content on changing the compressive strength was more significant than other variables, especially in the range of 0.3 to 0.35. Apart from this, increasing the portion of variables resulted in increasing the average cementitious paste thickness and the number of line segments, which both resulted in an increment of compressive strength. The PC mixture with 1.00% of PLS, W/C ratio of 0.40, and cement content of 350 kg/m3 had the maximum compressive strength of 18.35 MPa with reasonable porosity and permeability. This system is suitable as pavements in urban areas with light-traffic load, green spaces, and sidewalks to mitigate the anthropization impacts.

AbstractPopulation growth and urban expansion have increased impervious surfaces, leading to environmental issues such as stormwater runoff and groundwater depletion. Traditional concrete, while durable, contributes to these problems. There is a need for sustainable construction materials that can address environmental challenges and reduce the consumption of natural resources. Pervious concrete, enhanced with recycled aggregates (RCA) and supplementary cementitious materials (SCMs) like metakaolin (MK) present a potential solution. This study aims to improve the mechanical and durability properties of pervious concrete by incorporating RCA and MK, assessing their effects on workability, density, porosity, permeability, compressive strength and flexural strength. The incorporation of RCA resulted in increased aggregate porosity compared to natural aggregates. Workability was assessed using the slump test, density was measured, and porosity and permeability were evaluated. The results showed that incorporation of RCA generally decreased workability, density and strength, while the addition of MK improved these properties by refining the microstructure. Specifically, mixes with 10% MK demonstrated better performance in terms of increased compressive and flexural strengths, improved density and reduced porosity. The ANN model showed high accuracy in predicting compressive and flexural strengths. The study concludes that RCA and MK can enhance the mechanical and durability properties of pervious concrete. [ABSTRACT FROM AUTHOR]

Cement-based pervious concrete was prepared respectively with quartz powder, fine sand and silica fume as inorganic reinforcers. The influence of different inorganic reinforcers to the compressive strength, effective porosity and permeability coefficient of pervious concrete was investigated. The results show that the compressive strength of pervious concrete can be improved by adding certain amount of the inorganic reinforcing materials. In order to achieve the compressive strength of C25 and maintain good permeability, the content of quartz powder and fine sand should be 6% at least and 6%-8% of the total amount of coarse aggregate, and the content of silica fume should be 6%-10% of the total amount of cementitious material. Using the quadratic function equation, the permeability coefficient of pervious concrete can be obtained indirectly by measuring the effective porosity of pervious concrete. [ABSTRACT FROM AUTHOR]

This study explores the impact of varied cement doses (250, 275, 300, 325, and 350 kg/m³) and granular classes (Dmax of 8, 10, 12.5, and 20 mm) on pervious concrete characteristics. The concrete's fresh and hardened states are examined to identify the ideal cement dosage and granular class for optimal properties. Workability in the fresh state is measured using the slump test and air content analysis. In the hardened state, performance is assessed through water permeability, porosity, density, compressive strength, and electrical resistivity tests. The research reveals that granular class Dmax significantly affects pervious concrete properties. A smaller Dmax and lower cement dosage enhance workability, while in the hardened state, a smaller Dmax combined with higher cement dosage reduces porosity and water permeability and increases mechanical strength and density. The ideal combination of cement dose and granular class varies depending on the specific property under consideration. This study emphasizes the importance of carefully selecting granular class and cement dosage to achieve desired pervious concrete qualities. These findings provide valuable insights for practitioners aiming to enhance the sustainability and resilience of urban infrastructure using pervious concrete. [ABSTRACT FROM AUTHOR]

The contents of waste glass powder (WGP) (0%, 10%, 15%, 20%, 25%) and water-binder ratio (W/C) (0.24, 0.26, 0.28) were used as influencing factors, and the quality loss rate (Δm) and compressive strength loss rate (Δfc) were used as characterization parameters. The Ca/Si ratio and main element contents of C-S-H gels with different WGP content were investigated by energy dispersive spectrometry (EDS). The pore structure evolution characteristics of WGP composite cementing materials were investigated by low field nuclear magnetic resonance (NMR). Using Δfc as the index of frost resistance degradation and Weibull function, the frost resistance degradation of glass doped pervious concrete (WGP-PC) was modeled. The results show that, with WGP, for the same number of cycles, Δm and Δfc decrease and increase with the increase of WGP. Under the same WGP content, Δm and Δfc decrease first and then increase with the increase of W/C. After 100 freeze-thaw cycles, the samples with WGP content of 20% and W/C of 0.26 have the best freeze-resistance. Microscopic tests show that with the increase of WGP content, the Ca/Si ratio of C-S-H gel decreases at first and then increases with the increase of WGP content. The extreme value of Ca/Si is 2.36 when WGP is added by 20%. The pore volume of hardened paste with 20% WGP content decreased by 18.6% compared with that of cement system without WGP. The overall compactness of the specimen was improved. On the basis of the test data, a life prediction model was established according to Weibull function. The experiment showed that Δfc could be used as a durability degradation index, and the slope of the reliability curve became gentle after WGP was added, which reduced the damage degradation rate of PC. W/C was 0.26. It's about 5 000 hours. [ABSTRACT FROM AUTHOR]

AbstractThis research evaluates the impact of aggregate sizes on pervious concrete properties, comparing aggregates of 12.5 mm and 19 mm, as well as replacing natural aggregates with recycled aggregates set at 0% and 50%. Four types of pervious concrete were produced, and their properties were determined: density, porosity, permeability coefficient, compressive strength, flexural tensile strength, and abrasion resistance. The results indicate that water permeability is directly related to pore size and is influenced by aggregate size (90% of the variation in pervious concrete permeability) and, to a lesser extent, by recycled aggregate content (10% of the variation). Mixes with larger aggregates (19 mm) demonstrated higher permeability coefficients. Replacing natural aggregates with recycled aggregate did not significantly affect the mechanical properties of pervious concrete, highlighting the effectiveness of waste processing and mixing procedures, allowing for the incorporation of 50% of recycled aggregate. The concretes met the requirements of the American Concrete Institute, suggesting technically feasible conditions for sustainable practices in the construction industry. [ABSTRACT FROM AUTHOR]

The current study examines the strength and transport properties of reclaimed asphalt pavement (RAP) inclusive pervious concrete (PC) pavement mixes containing various industrial and agricultural wastes such as silica fume (SF), fly ash (FA), and bagasse ash (BGA). Apart from a conventional PC mix (containing natural aggregates) and a 100% RAP inclusive PC mix, seven different mixes were developed by mixing 100% RAP aggregates with SF (5 and 10%), FA (10 and 15%), and BGA (5, 10, and 15%) as partial replacements for ordinary Portland cement. The above-mentioned PC pavement mixes were investigated for density, porosity, permeability, compressive strength, modulus of rupture, and abrasion resistance. The interconnected pore structure of conventional PC and RAP-PC pavement mixes was investigated using 2D image analysis and X-Ray microcomputed tomography. Based on the laboratory results, it can be stated that the inclusion of RAP significantly improves the transport properties of PC pavement mixes with increased porosity and permeability values. This was primarily due to a more interconnected pore matrix and lesser isolated voids in the RAP-PC pavement mix. The addition of SF could only improve the strength parameters (compressive strength and modulus of rupture) of the RAP-PC pavement mix. In contrast, BGA inclusion was observed to improve its transport properties (porosity and permeability). Furthermore, the inclusion of SF, FA, and BGA in a 100% RAP-PC mix improved abrasion resistance. When compared to the conventional PC pavement mix, incorporating RAP aggregates blended with SF, FA, and BGA can reduce the production cost of 1 m3 PC by 30–61% and lower CO2 emissions by 13–21%. However, considering the strength and transport property requirements of PC mixes, as well as the economic and environmental viability, the present investigation recommends using 5% SF, 10% FA, and 10% BGA in a 100% RAP-PC pavement mix. [ABSTRACT FROM AUTHOR]

The recent emphasis on sustainability issues in construction materials has increased the interest to examine the effect of recycled aggregates on the performance of pervious concrete. This study investigated the effects of different types of recycled coarse brick aggregates (RCBAs), maximum RCBA size and using recycled fine brick aggregates (RFBAs) on the performance of pervious concrete. This has been done by testing void, density, compressive strength, splitting tensile strength, permeability, dust clogging and abrasion resistance. The quality of effluent passed through pervious concretes was also studied. According to the results, the usage of different types of RCBA decreased the compressive strength of pervious concrete, with the highest strength reduction of 55.3% which was obtained for 50% RCBA type A. A larger porous network of concretes by the incorporation of RCBA resulted in a higher permeability coefficient of up to 24.9%. Moreover, using RFBA in pervious concrete produces a much denser matrix and hence provides higher compressive and splitting tensile strengths and lower permeability coefficient. The permeability loss of pervious concretes due to dust clogging can also be decreased at 50% incorporation of different types of RCBA. Furthermore, results showed that RCBA types mainly influence the abrasion resistance of pervious concrete. Statement of Novelty: Different types of waste bricks may have different physical and mechanical properties which necessitated comprehensive experimental research about their performance in pervious concrete. To cover the gaps in this field, this research was conducted to investigate the effect of three major factors including (1) three different types of recycled coarse brick aggregates, (2) maximum aggregate size and (3) using recycled fine brick aggregates on the performance of pervious concrete. [ABSTRACT FROM AUTHOR]

Usage of pervious concrete in pavements, roof tops and other such applications has increased recently. This type of concrete aids in infiltration of excessive run-off in an ecofriendly manner. In this study, improvement of pervious concrete properties using industrial waste granite dust (GD) as partial cement replacement is analysed. Percentage of replacements so considered is in range of 0.5 – 2% and compared with reference mix properties. Results of the analysis show that replacement using GD for upto 1% increases the strength of the sample. Therefore, in the mix with 1% GD, a maximum strength of 13.5 MPa is observed which is 41% higher than that of mix without replacement. While GD replacement enhances the density, reduction in porosity, infiltration capacity, and water absorption is observed consequently. This variation in property is reasoned by the micro-filling effect of GD. In addition, dried powder samples are analysed using SEM/EDAX, FTIR, and XRD. Further analysis of water treatment ability of the pervious concrete specimens considering six parameters namely TSS, COD, BOD, TOC, TP, and TN show that GD replacement can potentially increase the pollutant removal ability of the mix than that of reference mix with maximum removal achieved for TP (77.9%) in sample with 2% replacement. [ABSTRACT FROM AUTHOR]

The current study examines the physical, mechanical, and durability of eco-efficient pervious concrete produced with partial and complete substitutions of natural aggregate (NA) by recycled aggregate (RA) waste from demolished concrete and porcelain. The experimental investigation assessed the workability (slump test), compressive strength, flexural strength, and tensile strength along with the concrete's water permeability, impact, and abrasion resistance. Seven mixes were examined; the first is a control mix with natural aggregate, and the other six are made with various RA ratios, including 30%, 70%, and 100%. The sand was also fully replaced by waste porcelain, even though the ratio of sand used in pervious concrete was low. The results revealed that using waste concrete and porcelain adversely affected the workability of fresh pervious concrete mixes, reducing it by approximately 14%. Furthermore, a decrease in the strength of pervious concrete was noticed, especially in the splitting tensile strength, where the reduction reached 32%. Moreover, the impact resistance of pervious concrete made with RA reduced by 29% compared to that made with NA; the same applies to durability, with an increase of 20% in weight loss. On the other hand, using both recycled concrete and recycled porcelain improved the permeability of the pervious concrete, which reached 30%. Pervious concrete made with waste concrete and porcelain can be an acceptable alternative to that made from natural aggregate due to its improved water permeability and positive environmental impact. However, further investigation is important to consider strength and durability enhancement. [ABSTRACT FROM AUTHOR]

The recycling of construction wastes holds significant importance both environmentally and economically. While extensive research has been conducted on aggregates derived from various wastes, the recycling of pervious concretes (PC) has been largely overlooked. This study addresses this gap by examining the porosity and mechanical properties of PC manufactured using aggregates obtained from recycled PC. The investigation focuses on three key factors: aggregate size (5/15, 10/15, and 15/25 mm size fractions), fiber inclusion (dosages of 0.1%, 0.2%, and 0.3% by volume), and aggregate type (limestone aggregate and recycled aggregate). Through image processing techniques, void characteristics including amount, structure, and homogeneity were quantified. Results indicate that the use of recycled aggregate led to a decrease in compressive strength ranging from 29% to 65%, depending on aggregate size fraction and fiber content. Porosity assessments revealed higher porosity in concrete utilizing recycled aggregate, with computer-based methods yielding values closely aligned with volumetric results. [ABSTRACT FROM AUTHOR]

Pervious concrete is desirable for water drainage in building systems, but achieving both high strength and good permeability can be challenging. Also, the importance of compaction energy is significant in determining the efficiency of pervious concrete. However, research on the development of unconfined compressive strength (UCS) prediction models for pervious concrete materials that incorporate compaction energy parameters remains unexplored. Therefore, this study aimed to balance strength and permeability while optimizing the compaction energy required for concrete production. A Central Composite Design (CCD) was used to design experiments within the response surface methodology (RSM) and evaluate the UCS, the porosity and permeability of pervious concrete specimens produced with varying cement content (280.00–340.00 kg/m3), the water-to-cement ratio (0.27–0.33), the aggregate-to-cement ratio (4:1–4.5:1), and compaction energy (represented by VeBe compaction time, 13–82 s). A regression model with goodness of fit (R2adjusted > 0.87) was calibrated to estimate the UCS of pervious concrete as a function of mix design parameters and VeBe compaction time (Tvc). This model can potentially guide field practices by recommending compaction strategies and mix designs for pervious concrete, achieving a desirable balance between mechanical strength and hydraulic permeability for building construction applications. [ABSTRACT FROM AUTHOR]

In the realm of sustainable construction materials, the quest for low-environmental-impact binders has gained momentum. Addressing the global demand for concrete, several alternatives have been proposed to mitigate the carbon footprint associated with traditional Portland cement production. Despite technological advancements, property inconsistencies and cost considerations, the wholesale replacement of Portland cement remains a challenge. This study investigates the feasibility of using alkali-activated slag (AAS)-based binders for two specific applications: structural plaster and pervious concrete. The research aims to develop an M10-grade AAS plaster with a 28-day compressive strength of at least 10 MPa for the retrofitting of masonry buildings. The plaster achieved suitable levels of workability and applicability by trowel as well as a 28-day compressive strength of 10.8 MPa, and the level shrinkage was reduced by up to 45% through the inclusion of shrinkage-reducing admixtures. Additionally, this study explores the use of tunnel muck as a recycled aggregate in AAS pervious concrete, achieving a compressive strength up to 20 MPa and a permeability rate from 500 to 3000 mm/min. The relationship between aggregate size and the physical and mechanical properties of no-fines concretes usually used for cement-based pervious concrete was also confirmed. Furthermore, the environmental impacts of these materials, including their global warming potential (GWP) and gross energy requirement (GER), are compared to those of conventional mortars and concretes. The findings highlight that AAS materials reduce the GWP from 50 to 75% and the GER by about 10–30% compared to their traditional counterparts. [ABSTRACT FROM AUTHOR]

Although pervious reduces surface runoff and replenishes groundwater resources, industrial applications are hindered by uncertainty in properties during mass productions. Most experimental studies correlated design parameters to performance parameters predominantly analysing porosity measured from water replacement method. This explains only a fraction of porosity and leads to inappropriate correlations between the influencing parameters. This study quantified porosity using a novel image analysis. 480 samples of pervious concrete were cast varying aggregate to cement ratio and compaction levels and performance parameters such as, wet-density, compressive strength, apparent, actual and effective porosities were assessed. The developed novel image analysis method facilitates accurate computation of porosity and actual, apparent and effective porosities was analysed quantified and optimised. An optimum A/C ratio was observed as 4.0 corresponding to 30 blows of compaction and a resultant actual porosity of approximately 0.2. Further the study establishes relationships between different types of porosities and their performance implications. [ABSTRACT FROM AUTHOR]

The utilization of dredged sediment (DS) as a transformative material in building applications presents an ideal consumption strategy. This study endeavors to create a novel ceramsite lightweight aggregate (LWA) through the co-sintering of DS and rice husks (RHs), further integrating this LWA into the construction of pervious concrete. Results revealed that the optimum production procedure for the DS-based LWA incorporated a 21% RH addition, a sintering temperature of 1100 °C, and a sintering duration of 21 min. Notably, the optimal ceramsite LWA, denoted as SDC-H, exhibited a cylinder compressive strength of 28.02 MPa and an adsorption efficiency for Pb2+ of 94.33%. Comprehensive analysis (encompassing bulk density, cylinder compressive strength, water absorption, and the leaching concentrations of heavy metals) confirmed that SDC-H impacted the specification threshold of high-strength light aggregate derived from solid waste (T/CSTM 00548-2022). Substituting 50% of SDC-H led to a diminution in the mechanical properties but an improvement in the dynamic adsorption capacity of the innovative pervious concrete, registering a mechanical strength of 26.25 MPa and a cumulative adsorption capacity for Pb2+ of 285 mg/g. These performances of pervious concrete containing 50% SDC-H might correlate with the evolution of an interconnected and open-pore structure. [ABSTRACT FROM AUTHOR]