scholarly journals Correlation between Concrete Compressive Strength and Rebound Number of River Bed and Crusher Run Coarse Aggregate in Pokhara Valley

2019 ◽  
Vol 1 (1) ◽  
pp. 29-33
Author(s):  
Tek Bahadur Katuwal

Concrete is principally composed of the mixture of cement, fine and coarse aggregates, and water and widely used for every building structure and other infrastructure. Aggregate has important functions as concrete making materials for the hardness and strength of concrete. The objective of this research was co – relation of compressive strength of concrete with Rebound number of crusher and river bed coarse aggregate in respect to the M20 grade of concrete with nominal mix. For this research, sample were taken from Hemja Crusher (HC), Hemja River Bed (HR), Kotre Crusher (KC), Kotre River Bed (KR) and considering sand from single source and commercially available single brand OPC cement. Fifteen cubes (150 mm × 150 mm×150mm) were cast for each sampled sources and the Compressive strength and Rebound number was determined after 7 days, 14 days and 28 days of curing. In this research, statistical analysis was carried out to determine the best fit curve by using IBM SPSS. Finally the outcomes of this research indicated that the relationship between rebound number and compressive strength curve is liner.

2019 ◽  
Vol 258 ◽  
pp. 04011
Author(s):  
Atur P. N. Siregar ◽  
Emma L. Pasaribu ◽  
I Wayan Suarnita

Coarse aggregate is the dominant constituent in concrete. Aggregate hardness is a variable needed to investigate in determining its effect on the critical stress intensity factors (KIC), dissipated fracture energy (Gf) and compressive strength (fc’) of the concrete. The hardness of coarse aggregate based on Los Angeles abrasion values of 16.7%., 22.6%, and 23.1% was used incorporated with Portland Composite Cement (PCC), and superplasticizer to create specimens. Cubes of 150x150x150 mm were employed to determine the fc’, and four beam sizes: 50x100x350 mm, 50x150x500 mm, 50x300x950 mm and 50x450x1250 mm were engaged to determine KIC and Gf. The fc’ and Gf of specimens manufactured by three different hardness of coarse aggregates were 45, 43, 40 MPa and 89.4, 54.0, 56.3 N/m respectively. KIC of specimens was 138.9, 119.4 and 114.1 MPa.mm1/2 for beam size of 50x100x350 mm; 148.2, 115.8 and 108.8 MPa.mm1/2 for beam size of 50x150x500 mm; 230.9, 183.1 and 157.9 MPa.mm1/2 for beam size of 50x300x950 mm; and 293.2, 248.1 and 244.3 MPa.mm1/2 for beam size of 50x450x1250 mm. Experimental results showed that decreasing hardness of coarse aggregate was found to have significant effect on the fracture toughness rather than on the compressive strength of concrete.


2021 ◽  
Vol 11 (4) ◽  
pp. 1952
Author(s):  
Euibae Lee ◽  
Jeongwon Ko ◽  
Jaekang Yoo ◽  
Sangjun Park ◽  
Jeongsoo Nam

In this study, the compressive strengths of concrete were investigated based on water content and aggregate volume fractions, comprising dune sand (DS), crushed sand (CS), and coarse aggregate (CA), for different ages. Experimental data were used to analyze the effects of the volume fraction changes of aggregates on the compressive strength. The compressive strength of concrete increases until the volumetric DS to fine aggregate (FA) ratio (DS/FA ratio) reaches 20%, after which it decreases. The relationship between changes in compressive strength and aggregate volume fractions was analyzed considering the effect factor of each aggregate on the compressive strength and at 2 conditions: (1) 0 < DS < CS < CA and (2) 0 < CA < CS < DS. For condition (1), when the effect factor of CA = 1, those of DS and CS were within 0.04–0.83 and 0.72–0.92, respectively, for all mixtures. For condition (2), when the effect factor of DS = 1, those of CS and CA were within 0.68–0.80 and 0.02–0.79, respectively.


2020 ◽  
Vol 211 ◽  
pp. 03007
Author(s):  
Auta Samuel Mahuta ◽  
Peter Emmanuel Aku

The search for natural and readily available structural material to meet the growing demand for ecologically friendly and smart structures is an ongoing development. In this background, an experimental study into the compressive strength of re-vibrated concrete made from pebbles as coarse aggregate is presented. Fifty-six (56) concrete cubes were cast adopting a re-vibration time lag interval of 10minutes for one hour, with a target strength of 15N/mm2. This comprised 28 cubes 100% granite and 28 cubes 100% pebbles as coarse aggregates respectively. Two curing ages were considered: 7 and 28 days. Results from the compressive strength tests of the cured specimens showed that: at successive time lag intervals there was an appreciable rise in compressive strength of concrete; observable was also a rise in the compressive strength with an increase of curing age. However, even though the maximum compressive strength of 25.64N/mm2 for 100%granite was achieved, that of 100%pebbles attained 23.33N/mm2, both at 60th minute of re-vibration time lag respectively. Hence, it can be suggested that 100% pebbles replacement for granite can be used to produce concrete with compressive strength of up to 23N/mm2 when revibrated.


2019 ◽  
Vol 16 (1) ◽  
pp. 52
Author(s):  
Jeriscot H. Quayson ◽  
Zakari Mustapha

Over one-third of the volume of concrete is occupied by coarse aggregate and any changes in coarse aggregate type can affect its strength and fracture properties. The paper examined the impact of coarse aggregates on compressive strength of concrete. Slump and compaction factor tests were conducted on the mixture of quartzite and crushed granite course aggregates, and quarry dust (fine aggregate). Nominal mix (1:2:3) was adopted and mix compositions were calculated by absolute weight method. Twelve (12) cubes (150x150mm) of each type of coarse aggregate were cast for 7, 14, 21, and 28 days to determine their compressive strengths. Quartzite was found to have the highest average compressive strength of 24.48N/mm2 with an average density of 2160kg/m3 , while compressive strength of crushed granite was 22.01N/mm2 with an average density of 2300kg/m3 on the 28 day of testing. Concrete made from granite had the highest workability, while concrete made from quartzite aggregate had the highest compressive strength. Densities and compressive strengths of the individual aggregates accounted for the variation in strengths of the concrete, due to differences in properties and strengths. In conclusion, the effect of any type of coarse aggregate on the compressive strength of concrete will be known and also enable contractors to determine the type of aggregate to be selected for a particular work. Keywords: Compaction factor test; slump test; strength; workability.


2014 ◽  
Vol 584-586 ◽  
pp. 1362-1365 ◽  
Author(s):  
Qin Liu ◽  
Xiao Na Zhang

Considering the high absorption of water is a distinctive feature of recycled crushed bricks coarse aggregate, the mixture ratio text of recycled concrete using crushed bricks as coarse aggregate is carried out, and the compressive performance is studied.The resert indicate , the strength grade of recycled concrete which using bricks as coarse aggregate can reach C20 and C25, characterisitic value of cubic concrete compressive strength at the age of 28 days are 21.2MPa and 27.55MPa;Based on regression analysis of test data , the formulas which estimated the strength of recycled coarse aggregates concrete are given out. Calculated values are in agreement with the measurement values, which can provide a reference for engineering application.


Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 556
Author(s):  
Muhammad Faisal Javed ◽  
Afaq Ahmad Durrani ◽  
Sardar Kashif Ur Rehman ◽  
Fahid Aslam ◽  
Hisham Alabduljabbar ◽  
...  

Numerous research studies have been conducted to improve the weak properties of recycled aggregate as a construction material over the last few decades. In two-stage concrete (TSC), coarse aggregates are placed in formwork, and then grout is injected with high pressure to fill up the voids between the coarse aggregates. In this experimental research, TSC was made with 100% recycled coarse aggregate (RCA). Ten percent and twenty percent bagasse ash was used as a fractional substitution of cement along with the RCA. Conventional concrete with 100% natural coarse aggregate (NCA) and 100% RCA was made to determine compressive strength only. Compressive strength reduction in the TSC was 14.36% when 100% RCA was used. Tensile strength in the TSC decreased when 100% RCA was used. The increase in compressive strength was 8.47% when 20% bagasse ash was used compared to the TSC mix that had 100% RCA. The compressive strength of the TSC at 250 °C was also determined to find the reduction in strength at high temperature. Moreover, the compressive and tensile strength of the TSC that had RCA was improved by the addition of bagasse ash.


Author(s):  
A.O Adeyemi ◽  
M.A Anifowose ◽  
I.O Amototo ◽  
S.A Adebara ◽  
M.Y Olawuyi

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.


2008 ◽  
Vol 3 (4) ◽  
pp. 130-137 ◽  
Author(s):  
R Kumutha ◽  
K Vijai

The properties of concrete containing coarse recycled aggregates were investigated. Laboratory trials were conducted to investigate the possibility of using recycled aggregates from the demolition wastes available locally as the replacement of natural coarse aggregates in concrete. A series of tests were carried out to determine the density, compressive strength, split tensile strength, flexural strength and modulus of elasticity of concrete with and without recycled aggregates. The water cement ratio was kept constant for all the mixes. The coarse aggregate in concrete was replaced with 0%, 20%, 40%, 60%, 80% and 100% recycled coarse aggregates. The test results indicated that the replacement of natural coarse aggregates by recycled aggregates up to 40% had little effect on the compressive strength, but higher levels of replacement reduced the compressive strength. A replacement level of 100% causes a reduction of 28% in compressive strength, 36% in split tensile strength and 50% in flexural strength. For strength characteristics, the results showed a gradual decrease in compressive strength, split tensile strength, flexural strength and modulus of elasticity as the percentage of recycled aggregate used in the specimens increased. 100% replacement of natural coarse aggregate by recycled aggregate resulted in 43% savings in the cost of coarse aggregates and 9% savings in the cost of concrete.


2020 ◽  
Vol 2 (1) ◽  
pp. 31-57
Author(s):  
Ni Ketut Sri Astati Sukawati

Concrete with various variants is a basic requirement in building a building. The concrete mixture is diverse depending on the planning made beforehand. The cement mixture is usually in the form of a mixture of artificial stone, cement, water and fine aggregates and coarse aggregates. Aggregates (fine aggregates and coarse aggregates) function as fillers in concrete mixtures. (Subakti, A., 1994). However, in building construction, additives are often added, but there is still a sense of uncertainty at the time of dismantling the mold and the reference before the concrete reaches sufficient strength to carry its own weight and the carrying loads acting on it. To overcome the time of carrying out work related to concrete, it is necessary to find an alternative solution, for example by looking for alternative ingredients of concrete mixture on the basis of consideration without reducing the quality of the concrete. From the results of previous studies it was stated that due to the partial replacement of cement with Fly Ash, the strength of the pressure and tensile strength of the concrete had increased (Budhi Saputro, A., 2008). Based on the description above, the author seeks to examine how the compressive strength of concrete characteristics that occur by adding additives Addition H.E in the concrete mixture and is there any additive Additon H.E effect on the increase in the compressive strength characteristic of the concrete. From the results of the study, it was found that the compressive strength of the concrete with the addition of additives HE was that after the compressive strength test of the concrete cube was carried out and the analysis of concrete compressive strength of 10 specimens, in each experiment a cube specimen was made with the addition of additons. HE with a dose of 80 cc, 120 cc, and 200 cc can accelerate and increase the compressive strength of concrete characteristics.


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