scholarly journals Roles of mortar volume in porosity, permeability and strength of pervious concrete

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Leo Gu Li ◽  
Jia-Jian Feng ◽  
Bo-Feng Xiao ◽  
Shao-Hua Chu ◽  
Albert Kwok Hung Kwan
Keyword(s):  
Open Porosity ◽  
Pervious Concrete ◽  
Fine Aggregate ◽  
Strength Performance ◽  
Cement Ratio ◽  
Interconnected Porosity ◽  
Water Cement Ratio ◽  
Major Factors

AbstractPervious concrete is designed to be porous to allow permeation of water and air for combating the environmental and drainage problems arising from urbanization. However, despite extensive research, it is still not clear how best to design pervious concrete mixes to achieve good concurrent permeability-strength performance. In a previous study, the authors found that there is a necessity to distinguish between interconnected porosity and open porosity, and between unsubmerged permeability and submerged permeability. In this study, based on the thinking that fine aggregate may be added to reduce the paste volume provided the fine aggregate is fine enough to form a coherent mass with the paste, further research was conducted to develop the mortar type pervious concrete with reduced paste volume and investigate the roles of the mortar volume in porosity, permeability and strength. A new series of concrete mixes with varying mortar volume were tested and the results revealed that the interconnected porosity is the major factor determining the permeability while the open porosity and water/cement ratio are the major factors determining the strength. More importantly, the mortar volume plays a key role in each performance attribute.

scholarly journals SUITABILITY OF BURNT AND CRUSHED COW BONES AS PARTIAL REPLACEMENT FOR FINE AGGREGATE IN CONCRETE

2017 ◽  
Vol 36 (3) ◽  
pp. 686-690
Author(s):  
NM Ogarekpe ◽  
JC Agunwamba ◽  
FO Idagu ◽  
ES Bejor ◽  
OE Eteng ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Fine Aggregates ◽  
Concrete Mix ◽  
Average Compressive Strength ◽  
Curing Age

The suitability of burnt and crushed cow bones (BCCB) as partial replacement for fine aggregate in concrete was studied. The percentages of replacements of fine aggregates of 0, 10, 20, 30, 40 and 50%, respectively of BCCB were tested considering 1: 2: 4 and 1: 11/2 :3 concrete mix ratios. The cow bones were burnt for 50 minutes up to 92oC before being crushed. Ninety-six (96) concrete cubes of 1: 2: 4 mix ratio and ninety-six (96) concrete cubes of 1 : : 3 mix ratio measuring 150x150x150mm were tested for the compressive strength at 7, 14, 21 and 28 days respectively. The research revealed that the BCCB acted as a retarder in the concrete. Water-cement ratio increased with the increase in the percentage of the BCCB. The mixes of 1:2:4 and 1::3 at 28 days curing yielded average compressive strengths in N/mm2 ranging from 16.49 - 24.29 and 18.71 - 29.73, respectively. For the mix ratios of 1:2:4 and 1:: 3 at 28 days curing age,  it was observed that increase in the BCCB content beyond 40 and 50%, respectively resulted to the reduction of the average compressive strength below recommended minimum strength for use of concrete in structural works.http://dx.doi.org/10.4314/njt.v36i3.4

Replacement of Sand By PVC Pipe Waste in Pavement Blocks

2018 ◽  
Vol 6 (7) ◽  
pp. 282
Author(s):  
Harshit Sangtani ◽  
Bhavini Jain ◽  
K Narayana Shenoy
Keyword(s):  
Compressive Strength ◽  
Specific Gravity ◽  
Water Absorption ◽  
Industrial Waste ◽  
Waste Material ◽  
Large Percentage ◽  
Fine Aggregate ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Pvc Pipe

In the present research an attempt has been made to replace some part of fine aggregate (sand) by an industrial waste, the industrial waste under investigation is produced when the PVC pipes are cut into the desired sizes, it is a very thin flaky substance having a specific gravity of 1.5.This material is very voluminous in nature, so it reduces the workability of concrete if used in large percentage. So this material cannot be used in very large quantities but it can successfully replace sand up to 20 percent when used in pavement blocks. Experimentation was done at a water-cement ratio ranging from 0.43-0.35.Compressive strength of the concrete has been evaluated at 7 days, 14 days 21 days and 28 days. Results of the investigation indicate that compressive strength of the concrete decreases as the percentage of PVC waste material increases.7 day strength of the concrete has varied from 35.55 MPa to 70.01 MPa and 28 day strength has varied from 56.7 MPa to 76 MPa. Water absorption was well within the limits and varied from 4.67% to 7.26% by mass. The results revealed that this waste material can satisfactorily replace sand in small amount also it is a great way to dispose of the waste and hence is a step forward in the quest for a greener concrete.

scholarly journals Effect of Water-Cement Ratio on the Properties of NaOH-Treated Rubberized Mortar

2020 ◽  
Vol 862 ◽  
pp. 135-139
Author(s):  
Dhabit Zahin Alias Tudin ◽  
Ahmad Nurfaidhi Rizalman
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Crumb Rubber ◽  
Fine Aggregate ◽  
Volume Percentage ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Effect Of Water ◽  
Hardened Properties ◽  
Rubberized Mortar

In this study, crumb rubber was used to partially replaced fine aggregate in mortar mixture by 5, 10, 15 and 20 volume percentage (vol%) with untreated and NaOH-treated crumb rubber. There were three (3) different water-cement ratio used which are 0.45, 0.50 and 0.55. Thus, the total number of mixtures was 27. The mortars were tested for flowability, compressive strength, flexural strength and density. Based on the results, higher water cement ratio and percentage of crumb rubber replacement increased the flowability but lowered the density, compressive strength and flexural strength of the rubberized mortar. It was also discovered that the significant effect of water-cement ratio on the fresh and hardened properties of the rubberized mortar was due to the water content in the mixture. Meanwhile, the use of NaOH as treatment to crumb rubber improved the flowability, compressive strength and flexural strength of the rubberized mortar.

scholarly journals Study on the Permeability of Recycled Aggregate Pervious Concrete with Fibers

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 321 ◽  
Author(s):  
Haitang Zhu ◽  
Chengcheng Wen ◽  
Zhanqiao Wang ◽  
Lan Li
Keyword(s):  
Compressive Strength ◽  
Permeability Coefficient ◽  
Polypropylene Fiber ◽  
Volumetric Analysis ◽  
Pervious Concrete ◽  
Recycled Aggregate ◽  
Fiber Types ◽  
Cross Sectional ◽  
Cement Ratio ◽  
Water Cement Ratio

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.

Effect of maximum grain size on value of modulus of rupture reactive powder concrete

2020 ◽  
Vol 26 (1) ◽  
pp. 1-8
Author(s):  
Widodo Kushartomo ◽  
Dewi Linggasari ◽  
Arianti Sutandi
Keyword(s):  
Concrete Beam ◽  
Aggregate Size ◽  
Modulus Of Rupture ◽  
Reactive Powder Concrete ◽  
Fine Aggregate ◽  
Steam Curing ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Buckling Failure ◽  
Reactive Powder

Modulus of rupture (R) is a measurement of a tensile strengh of a concrete beam. The value of R is affected by the size of fine aggregat grain, the density of the concrete beam and the water-cement ratio. The unit of R is MPa expressing the tensile strength of the concrete beam without reinforcement to withstand a buckling failure. The distance between the supports of the concrete beam should not be less than three times of the height of the beam. In this research the size of the concrete beam speciment was 100 mm x 100 mm x 350 mm, the maximum fine aggregate size was varied (300 µm, 425 µm, and 600 µm) and the water-cement ratio was also varied (0.25, 0.22 and 0,20). All speciments were cured by steam curing and were tested after seven days. The results show that the larger the size of the fine aggregat grain and the higher the water-cement ratio, the smaller the R.

Effect of Substitution of Crushed Waste Glass as Partial Replacement for Natural Fine and Coarse Aggregate in Concrete

2016 ◽  
Vol 866 ◽  
pp. 58-62 ◽  
Author(s):  
Oluwarotimi M. Olofinnade ◽  
Julius M. Ndambuki ◽  
Anthony N. Ede ◽  
David O. Olukanni
Keyword(s):  
Coarse Aggregate ◽  
Waste Glass ◽  
Glass Content ◽  
Partial Replacement ◽  
Hardened Concrete ◽  
Fine Aggregate ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Concrete Production ◽  
Concrete Mix

Reusing of waste glass in concrete production is among the attractive option of achieving waste reduction and preserving the natural resources from further depletion thereby protecting the environment and achieving sustainability. This present study examines the possible reuse of waste glass crushed into fine and coarse aggregate sizes as partial substitute for natural fine and coarse aggregate in concrete. The variables in this study is both the fine and coarse aggregate while the cement and water-cement ratio were held constant. The crushed glass was varied from 0 – 100% in steps of 25% by weight to replace the both the natural fine and coarse aggregate in the same concrete mix. Concrete mixes were prepared using a mix proportion of 1:2:4 (cement: fine aggregate: coarse aggregate) at water-cement ratio of 0.5 targeting a design strength of 20 MPa. Tests were carried out on total number of 90 concrete cube specimens of size 150 x 150 x150 mm and 90concrete cylinder specimens of dimension 100 mm diameter by 200 mm height after 3, 7, 14, 28, 42 and 90 days of curing. Test results indicated that the compressive and split tensile strength of the hardened concrete decreases with increasing waste glass content compared with the control. However, concrete mix made with 25% waste glass content compared significantly well with the control and can be suitably adopted for production of light weight concrete.

Development of Concrete Mix Design Nomograph Containing Polyethylene Terephtalate (PET) as Fine Aggregate

2013 ◽  
Vol 701 ◽  
pp. 12-16 ◽  
Author(s):  
Mohd Irwan Juki ◽  
Khairunnisa Muhamad ◽  
Mahamad Mohd Khairil Annas ◽  
Koh Heng Boon ◽  
Norzila Othman ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Splitting Tensile Strength ◽  
Mix Design ◽  
Fine Aggregate ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Concrete Mix Design ◽  
Mix Proportion ◽  
Concrete Mix

This paper describes the experimental investigation to develop the concrete mix design Nomograph for concrete containing PET as fine aggregate. The physical and mechanical properties were determined by using mix proportion containing 25%, 50% and 75% of PET with water cement ratio (w/c) 0.45, 0.55 and 0.65. The data obtained showed that the inclusion of PET aggregate reduce the strength performances of concrete. All the data obtained were combined into one single graph to develop a preliminary mix design nomograph for PET concrete. The nomograph consist of ; relationship between compressive strength and water cement ratio; relationship between splitting tensile strength water cement ratio; relationship between splitting tensile strength and PET percentage and relationship between compressive strength and PET percentage. The mix design nomograph can be used to assists in selecting the proper mix proportion parameters based on the criteria required.

scholarly journals A review of factors influencing performance of pervious concrete

2021 ◽  
Vol 73 (10) ◽  
pp. 1017-1030
Author(s):  
Stjepan Lakusic
Keyword(s):  
Void Ratio ◽  
Coarse Aggregate ◽  
Urban Environments ◽  
Cementitious Material ◽  
Pervious Concrete ◽  
Fine Aggregate ◽  
Sand Fraction ◽  
Conventional Concrete ◽  
Environment Friendly ◽  
Major Factors

Pervious concrete is an environment friendly solution for eliminating imperviousness-related drawbacks of conventional concrete. Pervious concrete mixes are predominantly composed of cement, coarse aggregate, and water. The partial or complete elimination of fine aggregate results in porous structure, which influences performance of pervious concrete. This article is aimed at reviewing major factors involved in the design of pervious concrete mixes, namely the compaction, aggregate to cementitious material ratio (ACR), sand fraction, water to cementitious material ratio (w/cm), size of coarse aggregate, and void ratio or porosity. The effects of various admixtures, replacement materials, and fibres, are also discussed. The results indicate that pervious concrete acts as an effective medium in promoting the sustainability of urban environments due to its multi-aspectual benefits.

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