Proportion Design of Concrete with Gravel-Crushed Proto-Machine-Made Sand

2011 ◽  
Vol 295-297 ◽  
pp. 436-439
Author(s):  
Chang Yong Li ◽  
Qiu Yan Sun ◽  
Feng Lan Li
Keyword(s):  
Mechanical Properties ◽  
Water Content ◽  
Fresh Concrete ◽  
Hardened Concrete ◽  
Cement Ratio ◽  
Water To Cement Ratio

Experiments were conducted to study the workability of fresh concrete and basic mechanical properties of hardened concrete with gravel-crushed proto-machine-made sand. Effects of water to cement ratio and content of stone powder were mainly considered. Based on the test and before, the values of practical parameters in formula are obtained for calculating mixed strength of concrete, and the beneficial range of water to cement ratio is proposed. Meanwhile, the reasonable water content, sand ratio and content of stone powder are also suggested.

Experimental Study on Mix Proportion of Fair-Faced Concrete for Urban Bridge

2012 ◽  
Vol 450-451 ◽  
pp. 383-386 ◽  
Author(s):  
Xiao Ke Li ◽  
Xiao Lu Ma ◽  
Xiao Yan Zhang
Keyword(s):  
Fly Ash ◽  
Surface Brightness ◽  
Fresh Concrete ◽  
Cement Content ◽  
Hardened Concrete ◽  
Surface Color ◽  
Cement Ratio ◽  
Mix Proportion ◽  
Water To Cement Ratio ◽  
The Cost

As the needs of fair-faced concrete structures for the ecological environment, this paper studies the mix proportion of fair-faced concrete in C30 strength grade by experiments. 13 concretes were designed and tested considering the water to cement ratio, the cement content, the percent of pulverized fly ash, the sand ratio, the water reducer and the formwork parting agent. The workability of fresh concrete, the compressive strength of hardened concrete at 7d, 28d and 56d, and the apparent quality as well as the surface brightness of concrete were got. The results show that the surface color and brightness of concrete were influenced successively by the cement content, the water to cement ratio, the sand ratio and the percent of pulverized fly ash. The use of formwork lacker may bring concrete into better brightness, while the mix oil may be a good selection considering the cost of parting agent. The suitable mix proportions of C30 concrete for urban bridge are proposed.

scholarly journals Effect of Water Cement Ratios on Compressive Strength of Palm Kernel Shell Concrete

2019 ◽  
Vol 2 (Issue 1) ◽  
Author(s):  
A.O Adeyemi ◽  
M.A Anifowose ◽  
I.O Amototo ◽  
S.A Adebara ◽  
M.Y Olawuyi
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Fresh Concrete ◽  
Palm Kernel ◽  
Hardened Concrete ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Palm Kernel Shell ◽  
Compressive Strength Of Concrete ◽  
Palm Kernel Shells

This study examined the effect of varying water cement ratio on the compressive strength of concrete produced using palm kernel shell (PKS) as coarse aggregate at different replacement levels. The replacement levels of coarse aggregate with palm kernel shells (PKS) were 0%, 25%, 50%, and 100% respectively. PKS concrete cubes (144 specimens) of sizes 150mm x 150mm x 150mm were cast and cured in water for 7, 14, 21 and 28 days respectively. A mix ratio of 1:2:4 was adopted with water-cement ratio of 0.45, 0.5, and 0.6 respectively while the batching was done by weight. Slump test was conducted on fresh concrete while compressive strength test was carried out on the hardened concrete cubes using a compression testing machine of 2000kN capacity. The result of tests on fresh concrete shows that the slump height of 0.45 water cement ratio (w/c) increases with an increase in PKS%. This trend was similar to 0.50 and 0.60 w/c. However, the compressive strength of concrete cube decreases with an increase in w/c (from 0.45 to 0.60) but increases with respect to curing age and also decreases with increase in PKS%. Concrete with 0.45 water-cement ratio possess the highest compressive strength. It was observed that PKS is not a good substitute for coarse aggregate in mix ratio 1:2:4 for concrete productions. Hence, the study suggest the use of chemical admixture such as superplasticizer or calcium chloride in order to improve the strength of palm kernel shells-concrete.

Kansas Water-Cement Ratio Meter: Preliminary Results

1996 ◽  
Vol 1532 (1) ◽  
pp. 73-79
Author(s):  
Mustaque Hossain ◽  
James Koelliker ◽  
Hisham Ibrahim ◽  
John Wojakowski
Keyword(s):  
Fresh Concrete ◽  
Accurate Determination ◽  
Hardened Concrete ◽  
Cement Slurry ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Concrete Mix ◽  
Predominant Factor ◽  
The One ◽  
Strength And Durability

The water-cement ratio of fresh concrete is recognized as the one factor that affects the strength and durability of an adequately compacted concrete mix. Although water-cement ratio is the predominant factor affecting strength of hardened concrete, currently no widely used, reliable method is available for measuring water-cement ratio in the field. A prototype device has been developed to measure the water-cement ratio of a plastic concrete mix. The method is based on the measurement of turbidity of water-cement slurry separated out of a concrete mixture by pressure sieving. Consistent results were obtained for air-entrained and non-air-entrained concrete. Statistical analyses of the test results have shown that this meter can measure the water-cement ratio of fresh concrete with an accuracy of ±0.01 on the water-cement ratio scale for a single test at a 90 percent confidence interval. The equipment will cost less than $10,000. If the method works as well in the field as it does in the laboratory, accurate determination of water-cement ratio could dramatically improve the ability of the concrete industry to ensure the quality of concrete construction.

Impact of Steel Fibers on Workability and Properties of UHPC

2016 ◽  
Vol 249 ◽  
pp. 57-61 ◽  
Author(s):  
Milan Rydval ◽  
Tomáš Bittner ◽  
Jiří Kolísko ◽  
Šárka Nenadálová
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
High Performance Concrete ◽  
Volume Fraction ◽  
Fresh Concrete ◽  
Mixture Design ◽  
Steel Fibers ◽  
Hardened Concrete ◽  
Hardened Cement ◽  
The Impact

This paper is focused on properties of fresh and hardened cement-based composite Ultra-High Performance Concrete with regard to different volume fraction of short brass coated steel fibers BASF MASTERFIBER® 482. Workability of fresh concrete and basic mechanical properties (tensile strength in bending, compressive strength) of hardened UHPC were found out. The workability of fresh concrete was measured by small mortar Haegermann cone. Percentage differences at cost were obtained at hardened concrete, too. The aim of the first experimental part of the research was the impact of volume fraction of steel fibers according to workability of fresh concrete and also according to mechanical properties of hardened UHPC with the same volume fraction of each component of the mixture, only the volume fraction of the steel fibers was different at each mixture. The mixture design of UHPC was changed to maintaining the workability of fresh concrete at the second part of the research. The workability at mixture with dosage of steel fibers of 300 kg/m3 measured by Haegermann cone was around 300 mm. In the framework of grant project GAČR 15-05791S the basic mechanical properties of hardened fine-grained cementitious composite material UHPC at small beams size of 160/40/40 mm and beams size 300/70/70 mm were determined. The aim of the research project was not only the determination of basic mechanical properties for each mixture design but also workability assessment and costs linked with higher amount of the volume fracture of steel fibers.

Effects of Fly Ash Addition on Compressive Strength and Flexural Strength of Foamed Cement Composites

2013 ◽  
Vol 795 ◽  
pp. 664-668 ◽  
Author(s):  
Roshasmawi Abdul Wahab ◽  
Mohd Noor Mazlee ◽  
Shamsul Baharin Jamaludin ◽  
Khairul Nizar Ismail
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Cement Composites ◽  
Volume Percent ◽  
Foaming Agent ◽  
Cement Ratio ◽  
Water To Cement Ratio

In this study, the mixing of polystyrene (PS) beads and fly ash as a sand replacement material in foamed cement composites (FCC) has been investigated. Specifically, the mechanical properties such as compressive strength and flexural strength were measured. Different proportions of fly ash were added in cement composites to replace the sand proportion at 3 wt. %, 6 wt. %, 9 wt. % and 12 wt. % respectively. The water to cement ratio was fixed at 0.65 meanwhile ratios of PS beads used was 0.25 volume percent of samples as a foaming agent. All samples at different mixed were cured at 7 and 28 days respectively. Based on the results of compressive strength, it was found that the compressive strength was increased with the increasing addition of fly ash. Meanwhile, flexural strength was decreased with the increasing addition of fly ash up to 9 wt. %. The foamed cement composites with 12 wt. % of fly ash produced the highest strength of compressive strength meanwhile 3 wt. % of fly ash produced the highest strength of flexural strength.

scholarly journals GGBS based alkali activated fine aggregate in concrete - Properties at fresh and hardened state

2021 ◽  
Vol 13 (1) ◽  
pp. 47-53
Author(s):  
G. Lizia Thankam ◽  
T.R. Neelakantan ◽  
S. Christopher Gnanaraj
Keyword(s):  
Mechanical Properties ◽  
Alkaline Solution ◽  
Elevated Temperatures ◽  
Fresh Concrete ◽  
Hardened Concrete ◽  
Fine Aggregate ◽  
River Sand ◽  
Complete Replacement ◽  
Concrete Properties ◽  
Fine Aggregates

Abstract Scarcity of the construction materials, peculiarly the natural river sand has become a serious threat in the construction industry. Though many researchers of developed and developing countries are trying to find alternative sources for the same, the complete replacement of the fine aggregate in concrete is crucial. Geopolymer sand developed from the Industrial waste (Ground granulated blast furnace slag - GGBS) is an effective alternative for the complete replacement of the natural sand. The GGBS based geopolymer sand (G-GFA) was tested for physical and chemical properties. Upon the successful achievement of the properties in par with the natural river sand, the fresh properties (fresh concrete density & slump) and hardened properties (compressive strength, tensile strength & flexural strength) of the concrete specimens developed with G-GFA were studied. The G-GFA is obtained by both air drying (AD-G-GFA) and oven drying (OD-F-GFA) after the dry mixing of the alkaline solution and GGBS for about 10 min. Thus, developed fine aggregates were studied separately for the fresh and hardened concrete to optimize the feasible one. Superplasticizer of 0.4% is included in the concrete mix to compensate the sightly hydrophilic nature of the fine aggregates produced. The mechanical properties of the concrete with G-GFA are observed to be more than 90% close to that of the concrete developed with natural river sand. Thus, both the fresh and mechanical properties of the G-GFA concrete specimens resulted in findings similar to those of the control specimen developed with natural river sand reflecting the plausibility of G-GFA as a complete replacement choice to the fine aggregate in the concrete industry. The flaky GGBS particles merge well with the alkaline solution at room temperature itself since the former gets dried at elevated temperatures. Thus, more feasible fresh concrete properties and mechanical properties were recorded for the AD-G-GFA than the OD-G-GFA.

scholarly journals Effect on the properties of fresh and hardened concrete made using fly ash geopolymer sand

2021 ◽  
Author(s):  
G. Lizia Thankam ◽  
T.R. Neelakantan ◽  
S. Christopher Gnanaraj
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Laboratory Tests ◽  
Water Adsorption ◽  
Fresh Concrete ◽  
Hardened Concrete ◽  
Fine Aggregate ◽  
Curing Process ◽  
River Sand ◽  
Curing Method

AbstractFly ash-based geopolymer fine aggregate is a potential replacement material for the natural river sand as it has similar physicochemical properties. This paper reports the experimental investigation of a study conducted using this fine aggregate in concrete with a focus on the properties of fresh and hardened concrete. The geopolymer fine aggregate was developed by air curing process and oven curing method. The oven curing method yielded relatively better mechanical properties in concrete specimens. The oven curing results in better behavior at later age also. Laboratory tests were conducted to ascertain the fresh concrete density, slump value, hardened concrete density, compressive strength, tensile strength, and flexural strength of the concrete specimens. The microstructure of the concrete specimens was analyzed using scanning electron microscope which indicated the agglomeration of the fly ash particles with few voids demonstrating the higher water adsorption capacity of the same. The unreacted particles noted in the microstructure later tend to merge with the lime obtained from the hydration of cement so as to develop improved later age mechanical strength. The results on mechanical properties of the concrete indicate much similar results to that of the concrete developed with the normal river sand, which confirms that the geopolymer sand is an ideal replacement choice for natural river sand.

Study on Mechanical Properties and Water Permeability of Recycled Aggregate Porous Concrete

2011 ◽  
Vol 366 ◽  
pp. 36-39 ◽  
Author(s):  
Chang Yong Li ◽  
Pin Nie ◽  
Feng Lan Li
Keyword(s):  
Mechanical Properties ◽  
Water Permeability ◽  
Orthogonal Test ◽  
Test Method ◽  
Recycled Aggregate ◽  
Cement Ratio ◽  
Porous Concrete ◽  
Test Parameters ◽  
Water To Cement Ratio ◽  
Orthogonal Test Method

Experiments were conducted to study the mechanical properties and water permeability of recycled aggregate porous concrete. The orthogonal test was designed considering four parameters including water to cement ratio, cement content, grain series of recycled aggregate and aggregate to cement ratio, each parameter was set at three levels. Performances of porous concrete were measured such as cubic compressive strength, flexural strength, continuous porosity and water penetration coefficient. Test results are analyzed on the basis of orthogonal test method, the optimum proportions corresponding to every test parameters are given out. The ranges of every test parameters are also proposed. It provides a reference for constructing porous concrete roads by recycled aggregate made of old concrete from dismantled buildings.

Basic Mechanical Properties of Concrete with Machine-Made Sand and Recycled Coarse Aggregate

2013 ◽  
Vol 357-360 ◽  
pp. 1102-1105 ◽  
Author(s):  
Shun Bo Zhao ◽  
Qi Guo ◽  
Guang Xin Li ◽  
Yan Feng Su
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Coarse Aggregate ◽  
Cement Ratio ◽  
Recycled Coarse Aggregate ◽  
Water To Cement Ratio ◽  
Current Specification ◽  
Current Design ◽  
Axial Compressive Strength

Experimental study was carried out on the concrete mixed with machine-made sand and recycled coarse aggregate (MSRAC), three strength grades of concrete were designed by changing the water to cement ratio as 0.36, 0.45 and 0.55, while the sand ratio varied in a range of 32%~38%, 32%~42% and 38%~44% successively. The workability and the mechanical properties such as compressive and splitting tensile strengths and elastic modulus of MSRAC were tested. The results show that although the mechanical properties of MSRAC were influenced by sand ratio, they were still controlled by the water to cement ratio. The ratio of axial compressive strength to cubic compressive strength and the elastic modulus of MSRAC basically satisfy the specifications of the current design code for concrete structures. It should be noticed that the tensile strength of MSRAC is lower than current specification, and tends to reduce with the increase of water to cement ratio.

Sign in / Sign up

Export Citation Format

Share Document