scholarly journals Study on the hydraulic conductivity by constant and falling head methods for pervious concrete

2015 ◽  
Vol 8 (3) ◽  
pp. 248-259 ◽  
Author(s):  
R. BATEZINI ◽  
J. T. BALBO
Keyword(s):  
Hydraulic Conductivity ◽  
Coarse Aggregate ◽  
Aggregate Size ◽  
Test Methods ◽  
Pervious Concrete ◽  
Test Results ◽  
Permeability Characteristics ◽  
Constant Head

The main goal of this paper is to show the analysis of the permeability characteristics of three different mixes of pervious concrete produced with the variation of the coarse aggregate size. Two different test methods were used to achieve the hydraulic conductivity of the samples: falling head and constant head permeability tests. Based on test results it is concluded that the pervious concrete mixes have shown to be good drainable materials. Besides, it was found that the permeability of the mixtures does not seem to depend on the size and gradation of the coarse aggregate.

scholarly journals Influence of Ash and Coconut Shell Against Compressive Strength and Permeability Characteristics of Pervious Concrete

2021 ◽  
Vol 12 (3) ◽  
pp. 4129-4138
Author(s):  
Suwendy Arifin Et.al
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Waste Material ◽  
Pervious Concrete ◽  
Coconut Shell ◽  
Fine Aggregate ◽  
Permeability Characteristics ◽  
Fine Aggregates ◽  
Reduced Density

Pervious concrete or non-fine concrete is a simple form of lightweight concrete made by eliminating the use of fine aggregates. As a result of not using fine aggregate in pervious concrete, then created a cavity filled with air and water can be passed. This cavity resulted in reduced density of the concrete as well as the reduced amount of area that needs to be covered by cement paste, thereby reducing the compressive strength. To increase the compressive strength of pervious concrete, in this study will utilize waste material. The waste material is the cocnut shell ash and coconut shell to strengthen the coarse aggregate bonds, so it is expected to increase the compressive strength along with the increase in permeability. Thus, in this study will replace part of the coarse aggregate with coconut shell with percentage 0%, 2,5%, 5%, 7,5%, 10% and partially replace cement with coconut shell ash with percentage 0%, 2,5%, 5%, 7,5%

scholarly journals Evaluation of the Effects of Coarse Aggregate Sizes on Concrete Quality

2017 ◽  
Vol 2 (10) ◽  
pp. 1 ◽  
Author(s):  
Lawrence Echefulechukwu Obi
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Aggregate Size ◽  
Test Results ◽  
Construction Sites ◽  
Coarse Aggregates ◽  
Appreciable Increase ◽  
Concrete Production ◽  
Concrete Quality

This work was necessitated by the observations made at construction sites where artisans and craftsmen were left alone in concrete production. It was discovered that they used inadequate quantity and size of coarse aggregates due to difficulty associated in the mixing as if the coarse aggregates were not needed in concrete production. The research has established that the coarse aggregates and their sizes play critical roles in the development of adequate strength in concrete. It was observed that with proper mixing, the slump test results did not witness shear or collapse type of slump rather there were true slump in all cases of the test. The workability decreased with slight differences when the coarse aggregate size was increased. The increase in the coarse aggregates yielded appreciable increase in the compressive strength. It can therefore be inferred that the quality of concrete in terms of strength can be enhanced through an increase in the coarse aggregate size when proper mix ratio, batching, mixing, transporting, placing and finishings are employed in concrete productions.

Aggregate Rugosity and Size Effect on Bituminous Mixes

1998 ◽  
Vol 1619 (1) ◽  
pp. 26-36 ◽  
Author(s):  
Taisir S. Khedaywi ◽  
Egons Tons
Keyword(s):  
Coarse Aggregate ◽  
Aggregate Size ◽  
Surface Characteristics ◽  
Fine Aggregate ◽  
Regression Equations ◽  
Test Results ◽  
Unconfined Compression ◽  
Unconfined Compression Test ◽  
Size Fractions ◽  
Coarse Aggregates

Higher costs and possible restricted availability of asphalt have stimulated research and discussion on how to reduce the amount of asphalt in bituminous mixes without sacrificing service. A hypothesis was proposed suggesting that for each coarse aggregate type with different surface characteristics there is a specific fine aggregate size that contributes to developing an interlocking mechanism between the surfaces of coarse aggregates when they are combined in a bituminous mix. To test this hypothesis, two types of coarse aggregates having different surface characteristics or rugosity, limestone and rounded gravel, were used. For each aggregate, two one-size fractions were tested—19 mm to 25 mm and 6.4 mm to 4.75 mm. One type of fine aggregate (limestone) with five one-size fractions was used. Four flow binder film thicknesses were chosen. The packing volume and rugosity concepts were the theoretical basis. Asphalt and aggregate mixes were tested in compression. The results were evaluated by the use of regression equations. Graphical presentations and illustrations were used as necessary. Unconfined compression test results showed that for one-size limestone coarse aggregate, the highest strength values were associated with No. 60 to No. 80 fines in the mix and for one-size rounded gravel coarse aggregate, the highest strength occurred when No. 200 to No. 270 fines were added to the mix. The highest strength was associated with 50 μm flow binder film thickness for all mixes.

Experimental Study on Size Effect in Strength of Pervious Concrete and its Associated Factor

2013 ◽  
Vol 634-638 ◽  
pp. 2684-2692 ◽  
Author(s):  
Xi Xi He ◽  
Shan Wu
Keyword(s):  
Compressive Strength ◽  
Size Effect ◽  
Dispersion Coefficient ◽  
Aggregate Size ◽  
Pervious Concrete ◽  
Impact Factors ◽  
Test Results ◽  
Ordinary Concrete ◽  
Splitting Strength ◽  
Mix Proportion

Based on the test results of compressive strength and splitting strength of three kinds of cubic specimens of pervious concrete whose side length is respectively 100mm, 150mm and 200 mm, the size effect on strength and its associated impact factors which include porosity and particle size of coarse aggregate analyzed. In the test, water cement ratio of every group of concrete mix proportion is constant. The main results are as follows: (1) Size effect on concrete of the pervious concrete is greater than that of ordinary concrete; (2) Size effect on splitting strength is greater than that on cubic compressive strength. (3) Size effect on splitting strength significantly increases with the increase of the aggregate size; (4) Weibull modulus m obtained in statistical test for compressive strength equals to 9, which should be more than twice the value of tensile strength. (5)Size effect on strength of concrete is related to its statistical discreteness, that is, the size effect is more obvious when the dispersion coefficient Cv is greater; (6)Weibull’s statistical size effect can be used to describe the size effect on strength indicators of concrete; Theoretical values of Weibull’s statistical size effect derived from the experiment agree with the test results well. (7) The abnormal trends of size effect are related to the abnormal changes of dispersion coefficient.

Laboratory Study of Hydraulic Conductivity for Coarse Aggregate Bases

1996 ◽  
Vol 1519 (1) ◽  
pp. 19-27 ◽  
Author(s):  
Brian W. Randolph ◽  
Jiangeng Cai ◽  
Andrew G. Heydinger ◽  
Jiwan D. Gupta
Keyword(s):  
Hydraulic Conductivity ◽  
Large Scale ◽  
Base Material ◽  
Testing Procedure ◽  
Test Methods ◽  
Standard Test ◽  
Coarse Grained ◽  
Test Results ◽  
Wide Range ◽  
Pavement Structures

Inadequate drainage of pavement structures has been identified as a primary cause of pavement distress. Hydraulic conductivity is the most important factor controlling drainage capability. Coarse grained materials have high values of hydraulic conductivity. ASTM and AASHTO standard test methods are limited for coarse materials used in pavement bases and subbases because of their high permeability and large particle sizes and the horizontal flow in the field conditions. A large scale horizontal permeameter and a testing procedure were developed and the range of hydraulic conductivities of six base and subbase specifications made up of three material types provided by the Ohio Department of Transportation were evaluated. A horizontal permeameter (305 × 305 × 457 mm) and a testing procedure were developed to reduce errors produced by sidewall leakage, partial saturation, measurement of small head differences, and interpretation of turbulent flow as laminar flow. Fifty-four samples were tested, including various gradations of nonstabilized, portland cement stabilized, and asphalt stabilized bases made of limestone, gravel, or slag materials. The results obtained were analyzed and compared with previous research, empirical relations, and field test results of similar base and subbase materials. The comparisons and analyses indicate that the permeameter and the procedure produce representative results. Test results indicate a wide range of hydraulic conductivities for gradations at each extreme of a specification. Effective porosities were also found to be as low as 6 percent for the fine gradation of a common limestone base material.

scholarly journals Evaluation of Changes in the Permeability Characteristics of a Geotextile–Polynorbornene Liner for the Prevention of Pollutant Diffusion in Oil-Contaminated Soils

2021 ◽  
Vol 13 (9) ◽  
pp. 4797
Author(s):  
Jeongjun Park
Keyword(s):  
Numerical Analysis ◽  
Contaminated Soils ◽  
Contact Time ◽  
Pressure Head ◽  
Test Methods ◽  
Pollutant Concentration ◽  
Test Results ◽  
Reactive Medium ◽  
Permeability Characteristics ◽  
Pollutant Diffusion

In this study, changes in the permeability characteristics of a geotextile–polynorbornene liner at different oil pollutant contact times were evaluated. Experiments and numerical analyses were performed, and ASTM D5887 and ASTM D6766 were applied as test methods. The test results show that, when the pollutant contact time and pressure head were 4 h and 75 kPa, the reaction between the geotextile–polynorbornene liner and the pollutant was almost complete. Moreover, a numerical analysis was used to measure the ratio of the concentration of the pollutant that permeated through the geotextile–polynorbornene liner to the initial pollutant concentration at different pollutant contact times. The ratio was between 70 and 83% after a pollutant contact time of 0.5 h and between 0.1 and 1.0% after 4 h. The test and numerical analysis results confirm that, as a reactive medium, the geotextile–polynorbornene liner can effectively prevent the diffusion of oil pollutants by changing its permeability characteristics.

Permeability and Porosity of Pervious Concrete Containing Blast Furnace Slag as a Part of Binder Materials and Aggregate

2017 ◽  
Vol 266 ◽  
pp. 272-277 ◽  
Author(s):  
Jul Endawati
Keyword(s):  
Blast Furnace ◽  
Portland Cement ◽  
Blast Furnace Slag ◽  
Coarse Aggregate ◽  
Aggregate Size ◽  
Pervious Concrete ◽  
Partial Substitution ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Furnace Slag

The use of industrial by-products could provide a feasible solutions for the construction industry to reduce the strain on supply of natural aggregate as well as achieving the concept of environmentally friendly binder material by replacing part of Portland cement. This paper reports the results of an experimental study, mainly on the permeability and porosity characteristic of pervious concrete developed by substituting 26% Portland cement with air-cooled blast furnace slag and replacing part of natural coarse aggregate with granular blast furnace slag of different aggregate size and different water/cement ratio. The pervious concrete with lower water cement ratio and 25% GBFS affected either the porosity or the compressive strength of the pervious concrete. As expected, the porosity increased in pervious concrete with bigger aggregate size, but decreased when the smaller aggregate size was used. Partial substitution of coarse aggregate with granular GBFS of the same gradation size did not affect the permeability coefficient. Specimens developed using water cement ratio of 0.34 and coarser aggregate size tend to have a greater water permebility compared with those of 0.3 water/cement ratio.

The Effect of Coarse Aggregate Gradation Degradation on the Mechanical Behavior of Asphalt Mixture

2013 ◽  
Vol 811 ◽  
pp. 223-227
Author(s):  
Yong Ye ◽  
Hong Kai Chen ◽  
Yi Zhou Cai
Keyword(s):  
Compressive Strength ◽  
Creep Behavior ◽  
Coarse Aggregate ◽  
Asphalt Mixture ◽  
Aggregate Size ◽  
Test Results ◽  
Creep Tests ◽  
Aggregate Gradation ◽  
Coarse Aggregates ◽  
Static Creep

The objective of this study is to investigate and evaluate the effect of coarse aggregates (aggregate size bigger than 2.36 mm) on the compressive strength and creep behavior of asphalt mixture. The variable that is mainly considered in the study is the gradation degradation of coarse aggregates. A kind of standard aggregate gradation and three kinds of degraded aggregate gradation mixture specimens are used. Uniaxial compression and static creep tests were realized at different loading conditions and temperatures. The test results on asphalt mixture showed that the compressive strength and creep behavior of asphalt mixture are significant affected by the different coarse aggregate gradations.

scholarly journals Flexural Performance and Toughness Characteristics of Geogrid-Reinforced Pervious Concrete with Different Aggregate Sizes

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2295
Author(s):  
Xiaoyu Meng ◽  
Qinghui Jiang ◽  
Ruyan Liu
Keyword(s):  
Flexural Strength ◽  
Concrete Beam ◽  
Evaluation Method ◽  
Aggregate Size ◽  
Pervious Concrete ◽  
High Porosity ◽  
Test Results ◽  
Flexural Performance ◽  
Four Point Bending ◽  
Cracking Performance

Pervious concrete is an environmentally friendly paving material to reduce surface runoff in urban construction. However, due to low flexural strength and cracking susceptibility caused by the high porosity, pervious concrete is only used in low-volume traffic roadways and parking lots for current service. This study investigated the permeability, strength, and flexural performance of pervious concrete with different coarse aggregate size, geogrid position, and geogrid layer number. Test results indicate that the geogrid placed at an appropriate position in pervious concrete improved the permeability and compressive strength. Four-point bending tests were conducted in the laboratory to evaluate the flexural performance and toughness characteristics of pervious concrete beam. Meanwhile, this study also proposed a new evaluation method to distinguish the contribution of geogrids and concrete mixture to the flexural toughness of pervious concrete beam at the pre-peak and post-peak stages by two toughness indices. Test results indicate that geogrids improved the flexural strength, deformability, and energy absorption capability of pervious concrete beam. The geogrids placed at both one-third and two-thirds of the heights of pervious concrete beam resulted in the optimum flexural performance. Besides, the small size (5–10 mm) aggregates were conducive to providing high flexural strength for the geogrid-reinforced pervious concrete beam, while the large size (10–15 mm) aggregates played a significant role in obtaining noteworthy post-cracking performance.

scholarly journals Clogging of pervious concrete pile caused by soil piping: an approximate experimental study

2018 ◽  
Vol 55 (7) ◽  
pp. 999-1015 ◽  
Author(s):  
Xinzhuang Cui ◽  
Jiong Zhang ◽  
Darhao Chen ◽  
Shucai Li ◽  
Qing Jin ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Relative Density ◽  
Conductivity Measurement ◽  
High Strength ◽  
Test System ◽  
Pervious Concrete ◽  
Laboratory Simulation ◽  
Sand Particle ◽  
Test Results ◽  
Potential Disadvantage

Due to their high permeability and high strength, pervious concrete piles (PCPs) can improve ground bearing capacity. However, clogging of pervious concrete in practice is a potential disadvantage. To investigate the clogging mechanism of PCPs due to sand piping, a series of laboratory simulation tests is conducted on a developed hydraulic conductivity test system. This testing demonstrates the effects of pervious concrete porosity, grading of fine movable particles, mix ratio of skeleton particles to movable particles, relative density of soil, and distance between PCPs on PCP clogging. The experimental test results show that the hydraulic conductivity of PCP decreases for approximately 70 min and then becomes relatively stable. In addition, it is observed that PCP clogging rarely occurs in cases of low pervious concrete porosity, small movable sand particle size, high sand relative density, and large pile distance. The results also show that measurement of electrical conductivity can be an alternative method of hydraulic conductivity measurement. Based on the test results, preliminary clogging models are proposed.

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