Showing papers on "Pervious concrete published in 2017"

Experimental Study on the Relationship between Permeability and Strength of Pervious Concrete

Abstract: Pervious concrete is widely used in various fields because of its high permeability. Strength and permeability are two important design parameters for pervious concrete, but limited researc...

Sediment transport and pore clogging of a porous pavement under surface runoff

Abstract: Drainage capacity of pervious concrete pavements will be greatly decreased once the pores become clogged. In this study, the mechanism of sediment clogging in the pores of the pervious concrete pavement under surface runoff is preliminarily revealed. Based on the modified permeability measurement system, a series of laboratory simulation tests are conducted to demonstrate the effects of porosity of pervious concrete, sediment size, depth of free surface flow, storm water runoff velocity on the permeability reduction due to clogging of the porous pavement. Within the scope of this study, the clogging is observed to more easily occur for specimens with large porosity, for well-graded sand as the clogging materials and large storm water depth. Horizontal runoffs has little influence on the final clogging ratio.

Investigation on composite polymer and silica fume rubber aggregate pervious concrete

Abstract: Many researchers are trying to obtain a pervious concrete with better physical and mechanical properties to be used in pavement. To achieve the optimized pervious concrete, different researchers have been using different materials, especially those waste materials which are existing worldwide, specifically in the compactly populated areas. Discarded tires are among them and rubber tire particles are being currently used to be considered as recycled waste materials. In this paper a combination of polymer, silica fume and rubber aggregate from rubber tire particles were used to obtain an optimized pervious concrete. The produced concrete’s properties were studied. The results indicate that this pervious concrete with the optimum replacing ratio of silica fume, polymer and rubber aggregate to mineral aggregate has higher flexural and compressive strength. The relative flexural and compressive strength of this pervious concrete has been increased 31% and 18% compared to the mineral aggregate pervious concrete. The most properties of this pervious concrete are enhanced. The impact resistance of this pervious concrete is improved 8% compared to mineral aggregate pervious concrete and the permeability meet the standard of Open-Graded Fraction Course. This pervious concrete significantly reduces the elasticity modulus of usual pervious concrete. The impact resistances

Comparing the effects of oil palm kernel shell and cockle shell on properties of pervious concrete pavement

Abstract: Nowadays, pervious concrete pavement is one of the best materials used in construction industry as a top layer of permeable pavement system to control the storm water at source In addition, increasing production of waste materials, increased the interest in utilising the waste materials for environmental and technical benefits Therefore, this paper compared the effect of using two different sizes of oil palm kernel shell (OPKS) and cockleshell (CS) as partial replacement of natural coarse aggregate on properties of pervious concrete pavement Thirteen mixtures were made, in which 630-mm natural gravel was replaced with 0, 25, 50 and 75% of 630-mm and 475-mm of both shells The relationships between the properties of pervious concrete mixtures was also determined The replacement of OPKS and CS as the natural aggregate decreased the compressive strength, while the angular shape of both shells caused higher void content and permeability as compared to those of control pervious concrete On the other hand, pervious concrete containing CS showed better properties than those of incorporating OPKS Apart from that, strong relationships between density, void content, permeability, compressive strength values indicated that they can be used as a pervious concrete quality control tests for prediction of properties of pervious concrete pavement before placement in the field

Development of Vegetation-Pervious Concrete in Grid Beam System for Soil Slope Protection.

Abstract: One of the most efficient and environmentally friendly methods for preventing a landslide on a slope is to vegetate it. Vegetation-pervious concretes have a promising potential for soil protection. In this study, the vegetation-pervious concrete with low alkalinity was developed and studied. Combined with a grid beam structure system, the stability and strength between the vegetation-pervious concrete and base soil are believed to be enhanced effectively. For improving plant adaptability, the alkalinity of concrete can be decreased innovatively by adding a self-designed admixture into the cement paste. The effects of the admixture content on alkalinity and compressive strength of the hardened pervious concrete were investigated using X-ray diffraction (XRD) and compression test, respectively. Meanwhile, the permeability of the vegetation-pervious concrete was studied as well. Through comparing with ordinary pervious concrete, the effect of low alkaline pervious concrete on vegetation growth was investigated in a small-scale field for ten weeks. The test results indicated that the alkalinity of the cement samples decreased with the increase of admixture content, and the vegetation grew successfully on previous concrete. By increasing the admixture content to approximately 3.6%, the compressive strength of pervious concrete was more than 25 MPa.

Studies on the properties of pervious fly ash–cement concrete as a pavement material

Abstract: The aim of this study is to investigate the effect of variation of cement content, partial replacement of cement by 10 and 20% of fly ash, partial replacement of coarse aggregate by fine aggregates (ranging from 5 to 15%) with the addition of plasticizer on the characteristics of pervious concrete. Class C fly ash was used for the production of pervious concrete, adopting ACI method of mix proportioning. Coarse aggregates of size 19 to 9.5 mm and 9.5 to 4.75 mm blended in the ratio of 60:40 respectively, a constant water—binder ratio of 0.3, a plasticizer of 0.8% by weight of cement were adopted. Density, compressive strength, flexural strength, split tensile strength, total voids, permeable voids, permeability by falling head method, sand blasting abrasion and cantabro abrasion were determined. Replacement of cement by fly ash (up to 20%) has reduced the compressive strength marginally, whereas, addition of fine aggregates (5–15%) has increased the above strength ranging from “marginal” to “high”...

Life Cycle Assessment of Concrete Products for Special Applications Containing EAF Slag

Abstract: Electric Arc Furnace (EAF) slags are steel slags that derive from the steel manufacturing process and are produced in large volumes (∼10% of the steel produced) worldwide, which pose an environmental threat when disposed in landfills. Their physicochemical characteristics (high density, roughness and resistance to fragmentation) favor their use in concrete products for special applications, especially where high resistance to abrasion is required and the increase concrete density is not a problem. The special concrete applications considered in this paper were industrial pavements, heavyweight concrete and pervious concrete paving blocks and all proposed products were designed in order to perform in a similar way as reference products with ordinary concrete. Then, in order to quantify the benefits arising from the utilization of an –otherwise useless– industrial by-product, a Life Cycle Assessment was carried out for each of the concrete products. One m3 or one m2 of concrete was selected as functional unit and a cradle-to-gate approach was followed for the LCA, including material extraction, transport and production and placement, stating the limitations and system boundaries used. Cost estimation for each of the products was also performed in order to assess their commercial viability. The results show that for industrial pavement construction, concrete with EAF slag aggregates has similar environmental load and cost with the reference concrete, while in the case of pervious paving blocks the use of EAF slag aggregates reduces the environmental load by 14% at a reduced cost, and for heavyweight concrete the environmental load is reduced by 44% at a significantly lower cost.

Laboratory-simulated investigation on thermal behaviours of permeable concrete pavements

Abstract: Impermeable pavements are recognised as one of the biggest contributors to the urban heat island effect, because they not only increase local temperatures through additional heat storage in the paving materials, but also reduce evaporative cooling on the ground surfaces. Therefore, permeable pavements are considered an effective solution for mitigating the thermal discomforts in hot climates. In this study, the thermal behaviours and performances of permeable concrete pavement were investigated with a series of simulation experiments in the laboratory. For comparison purposes, traditional Portland cement concrete (PCC) and Portland cement porous concrete (PCPC), which are commonly used in municipal pavements, were considered for the study. The thermal properties of those materials and their thermal impacts on the surroundings were discussed with specially designed tests. It is verified that the laboratory simulation tests and corresponding analysis methods proposed in the study could be utilised to charac...

Enhancing the Ability of Pervious Concrete to Remove Heavy Metals from Stormwater

Abstract: Catastrophic release of heavy metals from the King River mine in Colorado and the Minas Gerais dam in Brazil have brought to the forefront the importance of contaminant stabilization and re...

Mix design for improved strength and freeze-thaw durability of pervious concrete fill in Pearl-Chain Bridges

Abstract: Pearl-Chain Bridges are an innovative precast arch bridge technology which can utilize pervious concrete as fill material. The present study investigates how the mix design of the pervious concrete fill can be influenced by use of an air-entraining admixture, a high-range water reducing admixture, fibers, and by internal curing using lightweight aggregate to best possibly meet the requirements for a fill material in Pearl-Chain Bridges. The 28-day compressive strength, splitting tensile strength, shear strength, permeability, and freeze-thaw durability were determined and compared for eight different mixture proportions using two different sizes of granite coarse aggregate and at two different water-to-cement ratios. The specimens had an average void content of 24–28 %. Specimens containing air entraining and high-range water reducing admixtures were most workable, as determined by fresh density, and thus the easiest to place. The addition of a high-range water reducing admixture and lightweight sand (expanded shale) for internal curing improved the 28-day compressive strength and splitting tensile strength. The coarse aggregate gradation had a large influence on permeability; however, all tested permeabilities were high enough to drain the rain from a 100-year rain event in Denmark. The air entraining agent dosage used was not sufficiently high to create the necessary protective air content in the cement paste, and the freeze-thaw durability of the specimens were generally poor for the utilized test procedure; however, the mix design containing lightweight sand showed improved freeze-thaw durability compared to the other mix designs.

Pervious concrete brick with high strength

Abstract: The invention discloses a pervious concrete brick with high strength. The brick comprises the following raw materials: ordinary portland cement, broken stones, phosphogypsum, lithium slag powder, steel slag, coal ash, silica fume, iron tailing sand, metakaolin, mixed fibre, straw powder, a water reducer, poly(styrene-co-butadiene), a silicone acrylic emulsion, redispersible latex powder, macroporous resin, an epoxy resin adhesive, ethylene diamine tetra (methylene phosphonic acid) sodium, diisopropanolamine, sodium hyposulfite, calcium lignin sulphonate, and water. The pervious concrete brick with high strength has the advantages of high compressive strength, excellent water permeability, and good frost resistance.

Specialadmixture for pervious concrete and application ofspecialadmixture

Abstract: The invention discloses a specialadmixture for pervious concrete and application of the specialadmixture. Thespecial admixture comprises the following materials in weight percent: 5 to 15 percent (solid content) of a water reducing agent; 0.1 to 1 percent of a retarder; 0.1 to 1 percent of a thickener; 15 to 25 percent of an early strength agent; 25 to 50 percent of a water-repellent agent; 25 to 50 percent of rubber powder. The admixture overcomes the problem that the existing pervious concrete is not easy to transport bya tanker, and ensures that the phenomenon of blocking cannot occur when the pervious concrete is put into a tanker after the admixture is used, has excellent service behavior after the pervious concrete is discharged from the tanker, and has excellent cohesiveness, without phenomena of bottom sealing and hole blocking.

Laboratory Evaluation of Sound Absorption Characteristics of Pervious Concrete Pavement Materials

Abstract: This paper describes a laboratory study on the sound absorption characteristics of clogged and unclogged pervious concrete (PC) pavement materials compared with those of porous asphalt (PA) mixtures and those of conventional dense-graded asphalt and portland cement concrete pavement materials. Examined in this study were the effects of the mixtures’ initial porosity on their sound absorption characteristics and how these characteristics were affected by subsequent clogging of the mixtures. Four porosity levels of PC and PA were studied: 10%, 15%, 20%, and 25%. The mixtures with 20% porosity were tested for the effects of clogging. The test results showed that the shapes of sound absorption spectra of PC and PA materials were similar displayed high sound absorption values within the frequency range of 250 to 1,000 Hz. However, for all four porosity levels studied, the PC materials produced about 0.1 or 20% higher sound absorption coefficient values throughout the entire measured frequency range from 100 to...