Pervious Concrete Research Articles

Durability performance of low calcium Flyash-Based geopolymer concrete

This investigation aims to systematically evaluate the durability performance of 30 MPa grade of low calcium fly ash-based geopolymer concrete. The geopolymer concrete with fly ash as binder is manufactured using an alkaline activator solution (of 14 Molar and Na2Sio3/NaOH ratio of 2.5). The results were also compared with the Portland cement concrete of similar grade. The concrete samples were subjected to water absorption, water permeability, sorptivity, acid resistance, sulphate resistance, and rapid chloride penetration tests. Water absorption study findings revealed less water absorption by low calcium fly ash-based geopolymer concrete than Portland cement concrete. Also, the water permeability tests on geopolymer concrete indicated lower water penetration depth compared to Portland cement concrete. Sorptivity test results depict lower sorptivity by geopolymer concrete over ordinary Portland cement concrete. Geopolymer concrete shows better acid resistance and sulphate resistance performance than Portland cement concrete in terms of residual compressive strength. Rapid chloride penetration test results indicated moderate chloride penetrability of geopolymer concrete and low chloride penetrability by Portland cement concrete. In general, low calcium fly ash based geopolymer concrete outperformed Portland cement concrete in most durability indices, which led to the conclusion that low calcium fly ash based geopolymer concrete durability performance was superior to that of concrete of a similar grade made of Portland cement concrete.

Deep learning-based prediction for time-dependent chloride penetration in concrete exposed to coastal environment

The application of deep learning methods in civil engineering has gained significant attention, but its usage in studying chloride penetration in concrete is still in its early stages. This research paper focuses on predicting and analyzing chloride profiles using deep learning methods based on measured data from concrete exposed for 600 days in a coastal environment. The study reveals that Bidirectional Long Short-Term Memory (Bi-LSTM) and Convolutional Neural Network (CNN) models exhibit rapid convergence during the training stage, but fail to achieve satisfactory accuracy when predicting chloride profiles. Additionally, the Gate Recurrent Unit (GRU) model proves to be more efficient than the Long Short-Term Memory (LSTM) model, but its prediction accuracy falls short compared to LSTM for further predictions. However, by optimizing the LSTM model through parameters such as the dropout layer, hidden units, iteration times, and initial learning rate, significant improvements are achieved. The mean absolute error (MAE), determinable coefficient (R2), root mean square error (RMSE), and mean absolute percentage error (MAPE) values are reported as 0.0271, 0.9752, 0.0357, and 5.41%, respectively. Furthermore, the study successfully predicts desirable chloride profiles of concrete specimens at 720 days using the optimized LSTM model.

Pore Characteristic Design Method of High-strength Pervious Concrete Based on the Mechanical Properties and Rainstorm Waterlogging Resistance

Pore Characteristic Design Method of High-strength Pervious Concrete Based on the Mechanical Properties and Rainstorm Waterlogging Resistance

Properties of Pervious Concrete Made with Ferrochrome Slag as a Coarse Aggregate

Ferrochrome slag (FCS) is produced during the production of ferrochrome alloy, which is an essential component of stainless steel. FCS has favorable physical and chemical properties for use as an aggregate in place of natural aggregate in the production of conventional and pervious concrete. Previous studies reported that the mechanical properties of concrete are enhanced when FCS is used in place of natural aggregates. This study evaluated the performance of pervious concrete containing FCS aggregates to replace the natural aggregates (NA) in various percentages (0%, 25%, 50%, 75% and 100% by weight). The effect of FCS replacement ratios on the mechanical properties (compressive strength, flexural strength, and split tensile strength), water permeability in terms of infiltration rate and density of the pervious concrete were determined. The results showed that the coefficient of water permeability increases with the increase of ferrochrome slag content. However, the compressive strength and density are reduced due to the increase of the porosity of the concrete. The optimum replacement percentage of natural aggregate with FCS aggregate was found to be 75%. The study concluded that it is possible to produce sustainable pervious concrete by using waste ferrochrome slag.

Albedo of Pervious Concrete and Its Implications for Mitigating Urban Heat Island

Urban heat islands have become a growing concern in many cities around the world. Pervious pavements have been proposed as a potential solution to mitigate this effect, but their effectiveness in reducing surface temperatures is still uncertain. This experimental study aims to investigate the reflectivity of pervious concrete to determine whether pervious pavements are cooler than conventional pavements. To achieve this, five different Portland cement concrete mixes are used to create pervious concrete samples with varying porosity levels. The samples are sliced, and their spectral reflectance and albedo are measured and analyzed. The results showed that the albedo of dry pervious concrete decreases linearly with increasing porosity. Pervious concrete with a wet surface exhibits an albedo of approximately 0.15 which is independent of porosity. Additionally, fresh, dry pervious Portland concrete has an albedo ranging from 0.20 to 0.35, which is 0.10 to 0.20 lower than conventional fresh cement concrete. As a result of this low albedo, caution should be exercised when developing pervious concrete as a solution to combat the urban heat island effect, unless measures are taken to increase evaporation and offset the additional solar absorption resulting from the low albedo. Overall, these findings suggest that the use of pervious pavements alone may not be sufficient to reduce surface temperatures in urban areas. Future research should explore ways to increase the albedo of pervious pavements and develop effective strategies to mitigate the urban heat island effect.

Developing Lignite Pervious Concrete for Application in Pedestrian Walkways and Urban Runoff Treatment

In the present study, the mechanical characteristics and environmental aspects of lignite pervious concrete (LPC) in reducing stormwater pollution were investigated. Therefore, fine-grained lignite (0.6–1.2 mm) in various portions (up to 15% w/w of coarse aggregate) was added to the PC mixture. The workability, strength, cementitious paste thickness, and physical properties of LPC were examined for further application in urban areas with a focus on stormwater treatment. The statistical analysis of the results of ANOVA and visualization of the microstructure of LPC by means of scanning electron microscopy and energy-dispersive X-ray spectroscopy were also presented. The results showed that LPC is a sticky paste with no slump (0). Adding lignite also slightly reduced the compressive strength of LPC up to 23% lower than the control sample (13.8 MPa). In addition, the presence of lignite led to a considerable reduction in permeability (40%) and porosity (51%) compared to the control sample. It was also found that the increase in cementitious paste thickness resulted in an increase of the compressive strength, which was mainly concentrated between 0.3 and 1.8 mm. However, the performance of LPC in reducing stormwater contamination was promising. Sample L15, with the highest removal efficiency, reduced the chemical oxygen demand, total suspended solids, and turbidity up to 42.14%, 63.38%, and 67.24%, respectively, while no significant changes were observed in pH, total dissolved solids, and nitrate (NO3). In short, although adding lignite to PC caused a reduction in the strength and physical properties of LPC, its efficiency in reducing stormwater pollution is quite promising, and it is recommended for use in green spaces of urban areas.Graphical

Synergistic effect of aggregate gradation band and cement to aggregate ratio on the performance of pervious concrete

The present research particularly focuses to understand the synergistic effect of aggregate gradation band width and cement to aggregate ratio on the performance of conventional PC (CPC) and recycled aggregate based pervious concrete (RPC). Four various aggregate gradation bands, such as GB (22.5–4.75 mm), GB (22.5–10.0 mm), GB (22.5–12.5 mm) and GB (22.5–16.0 mm), and two different cement to aggregate ratios, such as 0.33 and 0.20, were used in this study. The research outcome inferences that the aggregate gradation band width and cement aggregate ratios have a great effect on the compressive strength, density, permeability and macroscopic pore characteristics of conventional PC and RPC. When using low cement to aggregate ratio of 0.20 along with these gradation bands, the compressive strength of CPC and RPC was found in the range of 6.34–12.89 MPa and 5.49–12.97 MPa, at the same while, the permeability of CPC and RPC was found in the range of 0.35–1.27 cm/s and 0.60–1.29 cm/s respectively and these values were also satisfied with in the limits as prescribed by ACI-522R-10. This paper elucidates the consensus behaviour of CPC and RPC from the material perspective that would enhance the utilization of CPC and RPC in the construction sector.

Mechanical behaviour of adsorbent pervious concrete using iron slag and zeolite as coarse aggregates

Using low-cost industry waste and mineral adsorbentsto produce Adsorbent Pervious Concrete (APC) is a sustainable solution with manifold environmental advantages.This study investigates the engineering properties of APC to widen the potential of its further utilization as a post-treatment step in refinery and wastewater treatment plants. For this reason, coarse aggregate in pervious concrete was replaced by coarse iron slag and zeolite in portions of 25%, 50%, 75%, and 100% by volume. The statistical analysis of variance (ANOVA) and visualization of the microstructure of APC using Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Spectroscopy (EDS) were also presented. Experimental results showed that replacing coarse aggregate with iron slag increased the APC’s strength, and the maximum value of compressive strength (16.80 MPa) occurred at 75% of replacement. Alternatively, increasing the zeolite proportion caused the strength reduction of APC, and the minimum compressive strength (9.40 MPa) happened in a sample with only coarse zeolite. The effect of cementitious paste thickness (CPT) on the compressive strength indicated that the iron slag did not markedly change the average of CPT, only a minor reduction compared to the control sample (0.30–1.5 mm), while zeolites caused considerable increase of average CPT (0.00–2.1 mm). Hence, increasing the average CPT resulted in reducing the APC compressive strength. Also, the specific gravity, resistance to compression, rectangular shape, and micropores on the surface of adsorbents affected the mechanical properties, porosity, and permeability of APC. All APC samples had a satisfactory porosity (more than 15%) and permeability (more than 1.17 mm/s), and the APC sample containing 75% of iron slag had the highest values. The role of adsorbents shape affects the porosity and permeability of APC, especially in the replacement portion of 50% and less, while for samples with more than 50% of adsorbents due to homogenization of the mix and having the same size as aggregates, the void content and infiltration rate approached the value of the control sample. Eventually, iron slag and zeolite based APC could potentially be used in wastewater treatment plants for post-treatment of wastewater as a new cleaner production.

EFFECTIVE UTILIZATION OF OMO-KURAZ SUGAR FACTORY BAGASSE ASH AS A SUSTAINABLE PARTIAL REPLACEMENT OF CEMENT IN CONCRETE FOR THE ETHIOPIAN CONSTRUCTIONS

This paper presents the recycling of sugar cane bagasse ash from the Omo-Kuraz sugar factory in Ethiopia as a cement replacement in concrete that offers a suitable solution to environmental issues related to waste disposal management and the emission of greenhouse gases. The influence of bagasse ash as a cementing material in concrete was examined by performing several strength and durability experiments. From a strength perspective, compressive and splitting tensile strength were tested. As part of durability properties, carbonation and chloride penetrability of bagasse ash concrete was studied. Bagasse ash-based concrete mixes were produced with different cement replacements (10% - 40%) and were tested at different curing periods. As per the strength and durability test results, bagasse ash can be utilized as a cementing material in concrete with 10% cement replacement as the optimum quantity. The durability test results revealed bagasse ash doesn’t have adverse effects from carbonation and chloride penetrability perspective on concrete. This indicates that the Ethiopian construction industry can consider bagasse ash as nonconventional cementing material. Keywords: Bagasse ash, Compressive strength, Sorptivity, Tensile strength, Workability

Study on Mass Erosion and Surface Temperature during High-Speed Penetration of Concrete by Projectile Considering Heat Conduction and Thermal Softening.

The mass erosion of the kinetic energy of projectiles penetrating concrete targets at high speed is an important reason for the reduction in penetration efficiency. The heat generation and heat conduction in the projectile are important parts of the theoretical calculation of mass loss. In this paper, theoretical models are established to calculate the mass erosion and heat conduction of projectile noses, including models of cutting, melting, the heat conduction of flash temperature, and the conversion of plastic work into heat. The friction cutting model is modified considering the heat softening of metal, and a model of non-adiabatic processes for the nose was established based on the heat conduction theory to calculate the surface temperature. The coupling numerical calculation of the erosion and heat conduction of the projectile nose shows that melting erosion is the main factor of mass loss at high-speed penetration, and the mass erosion ratio of melting and cutting is related to the initial velocity. Critical velocity without melting erosion and a constant ratio of melting and cutting erosion exists, and the critical velocities are closely related to the melting temperature. In the process of penetration, the thickness of the heat affected zone (HAZ) gradually increases, and the entire heat conduction zone (EHZ) is about 5~6 times the thickness of the HAZ.

Evaluating the Clogging Phenomenon in Pervious Concrete from January 2015 to December 2022

This study investigated the effects of clogging in Pervious Concrete (PC) from January 2015 to December 2022. Three different PC mixtures were used, which included coarse aggregate (4.75-9.5 mm), fine aggregate (0-20% weight of coarse aggregate), cement (340 kg/m3), and w/c ratio of 0.35. The samples were tested for compressive strength, permeability, and porosity. The best PC mixture containing 10% fine aggregate was selected for monitoring clogging over time. This mixture had a compressive strength of 24.7 MPa, permeability of 1.19 mm/s, and void content of 13.96%. A large-scale prototype of PC10 (10% of fine aggregate) measuring 3.5 m in length, 1.7 m in width, and 0.20 m in depth was constructed in Mashhad City, Iran. The in-place infiltration rate was measured on a monthly basis as the PC experienced different rainfall levels. The results showed that due to clogging, the infiltration rate was reduced by an average of 10% for the first four years of the experiments. This was followed by a substantial reduction of 20% in 2019 and 16.75% in 2020. Due to a high level of clogging, the infiltration rate was reduced by 5.02% and 2.23% in 2021 and 2022, respectively. However, the system still has the capacity to infiltrate at 1.14 mm/s. Although no maintenance was performed on the PC system, its efficiency and lifespan were substantially reduced. Nonetheless, the system can still be considered as an effective solution for stormwater management.

The compressive strength and damage mechanisms of pervious concrete based on 2D mesoscale pore characteristics

The compressive performance of pervious concrete depends largely on its pore characteristics. To study the effect of pore characteristics on the compressive strength of pervious concrete, different porosity specimens of pervious concrete were prepared. The Compression test and porosity test was performed on the pervious concrete specimens with a side length of 100 mm. A 2D numerical model of pervious concrete was developed by mesoscale pore characteristics of pervious concrete. The stress distributions and damage modes of pervious concrete during compression were analyzed by conducting uniaxial compressive simulation tests on the established model. The results indicate that the number of pores and maximum pore size of pervious concrete increase as the design porosity increases. The equivalent pore size follows a Gaussian distribution and the characteristic pore size is typically between 1 and 4 mm. The simulation results also indicate that porosity affects the stress distribution of pervious concrete mainly based on the solid phase percentage and contact area. The increase of the number of small pores (when the porosity is certain) is conducive to improving the uniformity of stress transmission, thereby enhancing the compressive strength of pervious concrete.

Role of supplementary cementitious materials in the development of sustainable pervious concrete

Pervious concrete is green concrete made with homogeneous mixture of cement, coarse aggregate, and water. It is highly porous in nature. It has a wide range of applications due to its porous nature and environmental benefits, including pavements, parking lots, footpaths, and cycle tracks. The strength and performance of pervious concrete depends on various factors such as cement content, aggregate gradation, and water cement ratio. However, the strength and durability of previous concrete are important factors to be considered to make it more sustainable, one method to achieve this is to replace the OPC with supplementary cementitious materials (SCM's). This not only helps in reducing the cement consumption there by reducing the emission of CO₂ in to the atmosphere but also improves the strength and durability of pervious concrete. The main aim of the present study is to develop a pervious concrete mix using mineral admixtures like Fly ash, GGBS and Metakaolin. to improve its performance. To achieve this, initially a pervious concrete mix was obtained using OPC only. Later, cement is replaced by different types and percentages of SCM's in Mix. Various parameters like density, compressive strength, permeability, porosity and resistance to acid attack were studied. For a 10% replacement with SCMs, there is a 41% to 45% increase in strength, but the strength change was more noticeable for a 20% replacement, which is 71%, 64%, and 59% for MK, FA, and GGBS, respectively. With regard to permeability amongst the replacements, FA 10% replacement has a permeability of 0.71 cm/sec, whereas MK 20% replacement 0.44 cm/sec. It is observed in the trend that mixes with admixtures performed better against the acid attack compared with the mix without admixtures. The mix M3F20 has lesser effect due to acid attack and has a minimum loss percentage of 4.70% and 8.0% for 2% and 5% acid dilutions respectively.

Influence of Calcined Clay Pozzolan and Aggregate Size on the Mechanical and Durability Properties of Pervious Concrete

Pervious concrete has been reported as a viable solution to reduce stormwater run-off, the heat-island effect, road noise, and pavement flooding. Previous researchers have focused on analysing the structural properties and functionality of pervious concrete. However, relatively few studies have been conducted into the addition of supplementary cementitious materials (SCMs), such as calcined clay, in pervious concrete and its effect on long-term durability. This paper has studied the effect of calcined clay pozzolan as a partial substitute for Portland cement in pervious concrete, together with the influence of coarse aggregate size. A water–binder ratio of 0.4 and aggregate–binder ratio of 4.0, as well as a superplasticiser content of 0.95%, were maintained for all mixes. Two sizes of coarse aggregates were used for this study: 9.5 mm and 20 mm. CEM-I cement was partly substituted with calcined clay in dosages of 0 to 30% in replacement intervals of 5%. The mechanical tests conducted included the split tensile test, compressive strength test, and flexural strength test. Durability measurements such as the rapid chloride permeability test (RCPT), thermal conductivity and sulphate resistance tests were also carried out. The mechanical properties of the pervious concrete followed a similar trend. The results showed that at 20% replacement with calcined clay, the compressive strength increased by 12.7% and 16% for 9.5 mm and 20 mm aggregates, respectively. The flexural strength improved by 13.5% and 11.5%, whereas the splitting tensile strength increased by 35.4% and 35.7%, respectively, as compared to the reference concrete. Beyond 20% replacement, the tested strengths declined. The optimum calcined clay replacement was found to be 20% by weight. Generally, pervious concrete prepared with 9.5 mm obtained improved mechanical and durability properties, as compared to those of 20 mm aggregates.

The development of the compressive strength of pervious concrete using sugarcane bagasse ash and flyash

This study's objective is to determine the effect on the characteristics of pervious concrete of partially replacing the cement in pervious concrete with either 10% fly ash and sugar cane bagasse ash as well as partially replacing the cement in pervious concrete with fine aggregates in varying proportions (ranging from 5%, 6%, 7%, 8%, 9%, and 10%). The construction of the various mixes required the use of fly ash from Class C, coarse aggregates ranging in size from 19 mm to 9.5 mm and 9.5 mm to 4.75 mm mixed in the ratio of 60:40, respectively, and a water to binder ratio that was maintained at 0.36 throughout the process. Moreover, the IS 10262-2009 method of mix proportioning was used in this experiment. With the use of the falling head method, we were able to determine the compressive strength, the total voids, the permeable voids, the density, and the permeability of the materials. This can be demonstrated by demonstrating that the range of compressive strength that was attained has potential applicability. In addition, the compressive strength was only marginally affected when cement was partially replaced by FA and SCBA (10%). On the other hand, the incorporation of fine aggregates at a percentage ranging from five to 5%, 6%, 7%, 8%, 9%, and 10% has resulted in an increase in strength that was previously described as “minor” to “high”. The incorporation of FA and SCBA into pervious concrete results in a reduction in the total amount of voids that are found inside the concrete.

Influence of corrosion rate on rust penetration in concrete

Influence of corrosion rate on rust penetration in concrete

EXPERIMENTAL INVESTIGATION OF PERVIOUS CONCRETE TO IMPEL IT IN THE INFRASTRUCTURE OF PAKISTAN

Pakistan is facing adverse environmental issues peculiarly in major cities. The condition gets worst during monsoon period when the whole city faces the urban flooding due to stagnation of storm water on all major streets and areas. The main reason is the lack of infra-structure to mitigate the crisis which is faced by the country during whole rainfall season. The introduction of Pervious Concrete in major pavement infra-structure can easily limit the problems of sump of rain water. As a part of road infrastructure, the upper layer of pavement can be pervious, making runoff water to move to sub-base. This paper offers the exploratory research to ascertain the compressive strengths and infiltration rate of different samples of Porous Concrete following the American Concrete Institute guidelines. The experiments were done with varying the properties of Pervious Concrete. The effects which were considered are curing time, mix proportion, percentage quantity of fine aggregate, ratio of water to cement and varying coarse aggregate size. The mix design ratio considered were 1:4, 1:5 and 1:6. For further experiment of infiltration rate, the custom slab was formed with dimensions 2’x1’x4” and was tested for all the desired ratios. For the purpose of cost comparison, a fixed size on land is kept as standard. The cost is compared for construction on the land, using three different materials: Pervious concrete, Traditional concrete and Asphalt premix.It was showed that the Traditional concrete is cheaper than the Pervious and Asphalt layer but Pervious concrete is also economical than Asphalt layer.

Applications of Pervious Concrete in Road Pavements

Abstract: Pervious concrete is a relatively new concept for rural road pavement, with increase into the problems in rural areas related to the low ground water level, agricultural problem. Pervious concrete has introduced in rural road as a road pavement material. Pervious concrete as a paving material has seen renewed interest due to its ability to allow water to flow through itself to recharge groundwater level and minimize storm water runoff. This introduction to pervious concrete pavements reviews its applications and engineering properties, including environmental benefits, structural properties, and durability. In rural area cost consideration is the primary factor which must be kept in mind. So that in rural areas costly storm water management practices is not applicable. Pervious concrete pavement is unique and effective means to meet growing environmental demands. By capturing rainwater and allowing it to seep into the ground. This This pavement technology creates more efficient land use by eliminating the need for retention.

Experimental Study of Pervious Concrete for Application to Pavement Base Course

Experimental Study of Pervious Concrete for Application to Pavement Base Course

Experimental study on size of aggregates, size and shape of specimens on strength characteristics of pervious concrete

Pervious concrete has a wide range of applications including pervious pavements, rigid drainage layers and water-free floor. In this paper, the influence of aggregate size, shape, and size of specimens on the mechanical properties of pervious concrete has been investigated. Tests on pervious concrete include direct compression on cubes and cylinders, splitting tension, and flexural tests on respective cylinders and prisms were carried out on three different mixes with aggregate sizes of 10, 12.5, and 20 mm. The height of specimens was kept as the primary variable whereas the aspect ratio was kept constant. Experimental results indicated that when aggregate size and height of specimen increases, compressive, splitting tensile and flexural strength decreases. Using Size effect models such as Linear model, Bažant's Size Effect Law and Modified Size Effect law, an approach is proposed to predict non-standard specimen strength from known standard specimen strength with high accuracy.