Showing papers on "Pervious concrete published in 2020"
TL;DR: In this paper, the effects of using recycled concrete aggregate and pozzolanic materials as a partial replacement of natural coarse aggregate (NCA) and cement, respectively, on the mechanical and permeability properties of fiber-reinforced pervious concrete mixes were investigated.
149 citations
TL;DR: In this article, the performance of paste and pervious concrete was investigated with a fixed compaction energy, as common in the field, using smooth river gravel aggregate and rougher limestone coarse aggregate.
102 citations
TL;DR: In this article, the influence of vinyl acetate and ethylene copolymer dispersible powder (VAE-P) on the performance and interfacial transition zone (ITZ) of pervious concrete, and explore the mechanism responsible for the resulted performance.
95 citations
TL;DR: In this article, the authors proposed a method to combine the beetle antennae search (BAS) and random forest (RF) algorithm to predict the permeability of pervious concrete.
Abstract: Pervious concrete is an environmentally friendly material that improves water permeability, skid resistance, and sound absorption characteristics. Permeability is the most important functional performance for the pervious concrete while limited studies have been conducted to predict permeability based on mix-design parameters. This study proposed a method to combine the beetle antennae search (BAS) and random forest (RF) algorithm to predict the permeability of pervious concrete. Based on the 36 samples designed in the laboratory and 4 key influencing variables, the permeability of pervious concrete can be obtained by varying mix-design parameters by RF. BAS algorithm was used to tune the hyperparameters of RF, which were then verified by the so-called 10-fold cross-validation. Furthermore, the model to combine the BAS and RF was validated by the correlation parameters. The results showed that the hyperparameters of RF can be tuned by the BAS efficiently; the BAS can combine the conventional RF algorithm to construct the evolved model to predict the permeability of pervious concrete; the cement/aggregate ratio was the most significant variable to determine the permeability, followed by the coarse aggregate proportions.
85 citations
TL;DR: In this article, a pervious concrete with carbonated ground steel slag powder as binder and crushed steel slags as aggregate was prepared, which provided the key material for construction of sponge city and explored a new approach to massively utilize steel slagg.
60 citations
TL;DR: In this article, the authors discuss the benefits of pervious concrete (PCP) and highlight the contribution of PCP to reduce the environmental impacts of built infrastructure, such as runoff mitigation, heat alleviation, energy conservation, and emissions reduction.
59 citations
TL;DR: In this paper, the use of recycled aggregates (RA) from construction and demolition waste and fly ash in pervious concrete was analyzed, and the results showed that the incorporation of 10% fly ash with 75% of recycled aggregate content showed an increase of 6% tendency to clogging compared to the reference concrete.
55 citations
TL;DR: In this article, a response surface methodology (RSM) is used to design the mix proportion of recycled aggregate pervious concrete, and three response surface models are optimized for practical application to find the suitable aggregate gradation and dosage combination of admixtures, and the verified experiment confirms that the model is effective.
50 citations
TL;DR: In this paper, the authors explored the production of a greener RCA-based pervious concrete by using recycled fine aggregates (RFA), where the percentage of waste in the concrete will be 72% by volume of the total concrete mixture constituents.
50 citations
TL;DR: To cater the demand as an alternative pavement material, pervious concrete exhibits an astonishing significance in the field of eco-friendly pavement design system, due to its overall hydrological properties as mentioned in this paper.
Abstract: To cater the demand as an alternative pavement material, pervious concrete exhibits an astonishing significance in the field of eco-friendly pavement design system, due to its overall hydrological ...
50 citations
TL;DR: Carbonation curing is a promising method for CO2 sequestration and strength improvement of cement-based materials as discussed by the authors, and it is shown that the carbonation dominantly occurs in the outer layer of the concretes.
Abstract: Carbonation curing is a promising method for CO2 sequestration and strength improvement of cement-based materials. For normal cement concretes, the carbonation dominantly occurs in the outer layer ...
TL;DR: In this article, the application of steel slag aggregate (SSA) in pervious concrete and the SSA enhancement effect was studied, and mesoscale finite element (FE) models containing zero-thickness Cohesive Zone Model (CZM) elements were used to study strengthening mechanisms and simulate cracking behavior.
TL;DR: In this article, an optimal mix design of pervious concrete containing TiO2-soaked recycled coarse aggregates (RCAs) in order to achieve the higher compressive strength was identified.
TL;DR: In this article, the authors explored the possibility of variation of different aggregate gradation types with different proportion of w/c ratios for the production of pervious concrete pavement (PCP) mixtures.
TL;DR: This study addresses the problem of how to accurately predict the two basic parameters of permeability coefficient and uniaxial compressive strength of concrete by applying a hybrid artificial intelligence model: multi-output least squares support vector regression (MOLSSVR).
TL;DR: In this paper, the effect of binder-to-aggregate ratio and different binders on the properties and microstructure of pervious concrete made with steel slag as aggregates was investigated.
TL;DR: The sound absorption of the concrete or cement-based material can be improved by creating porous structures in the materials through different methods, namely incorporating lightweight aggregate, creating physical voids, such as in pervious concrete or by inducing voids with the inclusion of foam in cellular concrete.
Abstract: Concrete, known as the second most consumed material in the world after water, is a versatile, inexpensive and durable construction material. Due to its high density, concrete is usually employed as rigid walls in buildings and also as sound barrier in highway. Researchers have proposed several methods to treat the concrete to also be capable of absorbing sound and thus improving the sound quality in a room. However, there exists limited information regarding the sound absorbing capability of concrete or more generally the cement-based materials. This paper reviews the sound absorption properties of various modified concrete materials from the existing published works. The influence of aggregate types and alteration of concrete ingredients on the acoustic properties of modified concrete materials are discussed. From the review, it is concluded that the sound absorption of the concrete or cement-based material can be improved by creating porous structures in the materials through different methods, namely incorporating lightweight aggregate, creating physical voids, such as in pervious concrete or by inducing voids with the inclusion of foam in cellular concrete. Another proposed method is also to incorporate large amount of hemp shiv to produce hemp concrete. A linear relationship is found to generally estimate the noise reduction coefficient as the function of the density of the materials using the data available from the published works.
TL;DR: In this paper, a series of test samples are produced using various design variables and then the mechanical strength and the pore properties of porous mixes are evaluated, and prediction equations are developed to estimate the porosity, permeability and the compressive strength of the pervious concrete mixes.
TL;DR: In this paper, the authors investigated the enhancing mechanism using SSA instead of limestone in pervious concrete from the perspective of microscopic characterizations, which includes improved strength, reduced width and densified structure.
TL;DR: In this paper, a uniaxial compression test was carried out to evaluate the damage and discuss the failure mechanism of porous concrete, and the changes in acoustic emission (AE) counts and energy were analyzed.
TL;DR: In this paper, the aggregate type and size and mineral admixtures are important factors influencing the permeability and the compressive strength of pervious concrete, and the optimum porosity and w/c for perviouscrete with both dolerite and granite are 18% and 0.25, respectively.
TL;DR: In this article, a new mixture proportion design method for pervious concrete was proposed to achieve the target compressive strength and permeability, based on the empirical equations established, and the design method has higher reliability, precision, and adaptability.
Abstract: Both the porosity-based method and the paste coating thickness-based method are aimed to design pervious concrete with target porosity. However, the properties of pervious concrete are partially related to its porosity, leading to their poor precision and repeatability. Actually, the skeleton structures of pervious concrete, which govern the permeability of pervious concrete, can be characterized by the number of contact zones, the width of contact zones, and the paste thickness between neighboring aggregates, and the mechanical properties are also influenced by the strengths of cement paste and aggregate. Therefore, the relationships between fundamental properties and the skeleton structures of pervious concrete must be clarified prior to the mixture proportion design. In the present study, structurally-designed pervious concretes were prepared by rationally changing their skeleton structures. Then the compressive strength and permeability of pervious concretes were measured and corelated to their skeleton structures and the strength of cement paste. Based on the empirical equations established, a new mixture proportion design method for pervious concrete was proposed to achieve the target compressive strength and permeability. Experimental validation presented that the design method has higher reliability, precision, and adaptability.
TL;DR: In this article, an improved single ring infiltrometer is used to measure the permeability of a newly constructed pervious pavement, and different maintenance methods are designed to find the best combination, including different pressure wash, sweep-+-vacuum and pressure wash+vacu-uum.
TL;DR: The pore tortuosity of the pervious concrete was determined by volumetric analysis and two-dimensional cross-sectional image analysis, and general relations between the permeability coefficient and porosity Tortuosity are constructed.
Abstract: Pervious concrete is considered to be porous concrete because of its pore structure and excellent permeability. In general, larger porosity will increase the permeability coefficient, but will significantly decrease the compressive strength. The effects of water-cement ratio, fiber types, and fiber content on the permeability coefficient, porosity, compressive strength, and flexural strength were investigated. The pore tortuosity of the pervious concrete was determined by volumetric analysis and two-dimensional cross-sectional image analysis. The concept and calculation method of porosity tortuosity were further proposed. Results show that the permeability coefficient of the pervious concrete is the most suitable with a water-cement ratio of 0.30; the water permeability of the pervious concrete is influenced by fiber diameter. The permeability coefficient of pervious concrete with polypropylene thick fiber (PPTF) is greater than that with copper coated steel fiber (CCF) and the polypropylene fiber (PPF). The permeability coefficient is related to tortuosity and porosity, but when porosity is the same, the permeability coefficient may be different. Finally, general relations between the permeability coefficient and porosity tortuosity are constructed.
TL;DR: In this article, the authors compared various methods for measuring the infiltration rate of pervious concrete in isolation, including the constant head, falling head, and modified ASTM C1701 test, and found that the sample-to-sample variation in infiltration rate is typically much larger than the experimental uncertainty present in a given test method.
TL;DR: In this article, the use of waste glass (WG) in pervious concrete, aiming to maximize the reuse of WG in concrete, was presented, and the effect of the WG aggregate replacement and aggregate to binder ratio (A/B) on the mechanical properties, permeability, thermal conductivity, volume stability and pore structure were determined.
Abstract: This study presents the use of waste glass (WG) in pervious concrete, aiming to maximizing the reuse of WG in concrete. The effect of WG aggregate replacement and aggregate to binder ratio (A/B) on the mechanical properties, permeability, thermal conductivity, volume stability and pore structure were determined. The microstructures with and without immersing in 1 M NaOH 80 °C solution were also characterized. The results showed that the compressive strength decreased with the increasing replacement of WG aggregate and A/B, but the water permeability was improved. The presence of WG aggregate was effective in improving the permeability due to the smooth surface of WG aggregate and broader pore size distribution. With 100% WG aggregate replacement with A/B of 2–4, the permeability and compressive strength of the pervious concrete were still higher than the requirement of JIS A 5371. Another encouraging result was that the incorporation of a large amount of WG aggregate showed limited alkali-silica reaction (ASR) expansion in the pervious concrete, which was attributed to the low water to binder ratio, high amount of supplementary cementitious materials (SCMs), and accommodation effect of the porous structure to relieve the expansion pressure caused by ASR gel. Meanwhile, pervious concrete with a WG content of 80.95% could be produced with satisfactory functional properties and low thermal conductivity. Therefore, it is feasible to use WG aggregate to completely replace natural aggregate to achieve the maximum reuse of WG for producing pervious concrete.
TL;DR: In this article, the authors identify and characterize the phenomenon of clogging of pervious concrete (PC) considering laboratory and field conditions, and propose an analytical model to describe the clogging.
Abstract: During rainfall, different types of sediments are transported (organic and inorganic) that end up prejudicing the hydraulic efficiency of materials such as pervious concrete (PC). Sediments tend to accumulate on the surface of the material and its internal pore structure causing a decrease in permeability. This phenomenon is known as clogging. This study aims to identify and characterize the phenomenon of clogging of PC considering laboratory and field conditions. In that sense, a PC mix and three types of sediment (sand (S), clay (C), and mixture of both (S + C)) were considered. Two types of permeability tests were adapted to induce the clogging and estimate the permeability reduction: the constant head test (laboratory), and the ASTM C1701 (field). Finally, different rates of clogging (low, medium and high) were considered. Considering the type of sediments, the finer they are the higher is the influence on the clogging phenomenon, reaching maximum permeability reductions greater than 95%. Considering the rate of clogging, the results show that low rate entails higher clogging. On the other hand, an analytical model to describe the clogging was proposed. This predicts efficiently the reduction of permeability considering the type and concentration of sediment. This model was proposed with experimental data obtained and validated with results from other investigations. The model aims to be used for engineers to design PC considering their life span and maintenance.
TL;DR: In this article, the relationship among porosity, permeability, compressive strength, durability and the pore structure characteristics of pervious concrete is investigated and the influences of basalt fiber and fine aggregate on the perviouscrete are also discussed.
Abstract: Pervious concrete has been widely used in parking lots and other lightweight streets. Performances of pervious concrete are strongly dependent on its pore structure characteristics. This paper investigates the relationship among porosity, permeability, compressive strength, durability and the pore structure characteristics of pervious concrete. The influences of basalt fiber and fine aggregate on the pervious concrete are also discussed. Pervious concrete specimens with different pore structures were prepared by combining basalt aggregate with size of 5–10 mm and 10–15 mm at different proportion. The pore structure characteristics such as area porosity, pore sizes, and pore distribution of pervious concrete were obtained and analyzed using image analysis method. Experimental results showed that the pore structure characteristics of pervious concrete have effects on its mechanical and durability behaviors. Homogeneous pore distribution and large distances between pores increase the compressive strength and improve freeze–thaw durability of pervious concrete. Due to the difference in the internal pore structure of pervious concretes, specimens with similar volumetric porosities had different permeability coefficients. A series of numerical models were regenerated through a MATLAB code using pore structural parameters derived from the image analysis method, then the numerical models were fed to ANSYS for meshing and further simulation. The comparison of the simulation and experimental results showed close accuracy, which verified the applied simulation analysis method based on image analysis technology.
TL;DR: In this article, the service life of permeable pavements is strongly influenced by the infiltration capacity reduction produced due to the progressive clogging of the interconnected pores, and the authors focused on the eff...
Abstract: Service life of permeable pavements is strongly influenced by the infiltration capacity reduction produced due to the progressive clogging of the interconnected pores. This study focused on the eff...