scholarly journals Towards Sustainable Self-Compacting Concrete: Effect of Recycled Slag Coarse Aggregate on the Fresh Properties of SCC

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Hisham Qasrawi
Keyword(s):  
Steel Industry ◽  
Coarse Aggregate ◽  
Steel Slag ◽  
Fresh Properties ◽  
Self Compacting Concrete ◽  
Air Content ◽  
Coarse Aggregates ◽  
Slump Flow ◽  
Natural Aggregates ◽  
The Impact

Steel industry results in accumulation of steel slag wastes causing severe environmental problems. These wastes can be recycled and replace natural aggregates resulting in sustainable green concrete. In this research, natural aggregates in self-compacting concrete (SCC) are replaced, wholly or partly, by steel slag coarse aggregates that were produced by crushing by-product boulders obtained from the steel industry. Fresh properties, (workability, stability, bleeding, air content, and fresh density) are the crucial ones that affect the final properties of SCC. Therefore, it becomes important to evaluate the impact of SSA on the fresh properties of SCC mixes. The properties that are studied include stability, flowability, blocking, segregation, and bleeding. Furthermore, air content and fresh density are measured. In order to evaluate the impact of SSA on SCC properties, several testing methods are employed. Slump flow, V-funnel, column segregation, sieve segregation, segregation probe, U-shaped box, and VSI tests have been used in the study. The results show that it is possible to produce SCC using steel slag aggregate. Hence, green sustainable SCC can be produced. The results show that the fresh properties become sensitive for SSA replacement ratios exceeding 50%.

scholarly journals Effect of Fly Ash and Un-crushed Coarse Aggregates on Characteristics of SCC

2020 ◽  
Vol 6 (4) ◽  
pp. 693-701 ◽  
Author(s):  
Muneeb Ayoub Memon ◽  
Noor Ahmed Memon ◽  
Bashir Ahmed Memon
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Coarse Aggregate ◽  
Flow Time ◽  
Fresh Properties ◽  
Self Compacting Concrete ◽  
Coarse Aggregates ◽  
Slump Flow ◽  
Crushed Aggregate ◽  
Better Than

This research paper discusses the change in the workability and strength characteristics of Self Compacting Concrete (SCC) due to addition of fly-ash and use of un-crushed Coarse Aggregate (CA). Laboratory based experimental work was carried out by preparing 12 SCC mixtures among which six mixtures contained crushed aggregate and other six mixtures contained un-crushed coarse aggregate. A total of 550 kg/m3 binder content and fixed Water-Binder (W/B) ratio as 0.35 were used. Two mixtures were controlled by using Portland Cement (PC) and other ten mixtures contained PC and Fly Ash (FA). Slump flow time, slump flow diameter and J-ring height tests were conducted to study the fresh properties of SCC. Furthermore, compressive strength was calculated at 7, 14 and 28 days of curing. The outcomes indicated that the slump flow time, slump flow diameter and J-Ring height for all the mixes are within the limits specified by EFNARC guidelines. The compressive strength of SCCs depends upon dosage of fly ash. Compressive strength for SCCs with crushed CA was better than obtained in case of un-crushed CA. The maximum compressive-strengths were observed as 64.58 MPa and 58.05 MPa for SCC with crushed and un-crushed CA respectively.

Experimental Study on the Workability of Self-Compacting Granite and Unwashed Gravel Concrete

2017 ◽  
Vol 31 ◽  
pp. 69-76
Author(s):  
Gideon O. Bamigboye ◽  
David O. Olukanni ◽  
Adeola A. Adedeji ◽  
Kayode J. Jolayemi
Keyword(s):  
Experimental Study ◽  
Coarse Aggregate ◽  
Mix Design ◽  
Fine Aggregate ◽  
Self Compacting Concrete ◽  
Consistency Test ◽  
Coarse Aggregates ◽  
Slump Flow ◽  
Filling Ability ◽  
Passing Ability

This study deals mainly with the mix proportions using granite and unwashed gravel as coarse aggregate for self-compacting concrete (SCC) and its workability, by considering the water absorption of unwashed gravel aggregate. Mix proportions for SCC were designed with constant cement and fine aggregate while coarse aggregates content of granite-unwashed gravel combination were varied in the proportion 100%, 90%/10%, 80%/20%, 70%/30%, 60%/40%, 50% /50%, represented by SCC1, SCC2, SCC3, SCC4, SCC5 and SCC6. 100% granite (SCC1) serves as the control. The workability of the samples was quantitatively evaluated by slump flow, T500, L-box, V- funnel and sieve segregation tests. Based on the experimental results, a detailed analysis was conducted. It was found that granite and unwashed gravel with SCC1, SCC2 and SCC3 according to EFNARC (2002) standard have good deformability, fluidity and filling ability, which all passed consistency test. SCC1, SCC2 and SCC3 have good passing ability while all mixes were in the limit prescribed by EFNARC (2002). It can be concluded that the mix design for varying granite-unwashed gravel combination for SCC presented in this study satisfy various requirements for workability hence, this can be adopted for practical concrete structures.

EFFECTS OF BAMBOO FIBERS AND LIMESTONE POWDER ON FRESH PROPERTIES OF SELF-COMPACTING CONCRETE

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Anthony Nkem Ede ◽  
Obatarhie Oshogbunu ◽  
Oluwarotimi Michael Olofinnade ◽  
Kayode Joshua Jolayemi ◽  
Solomon Olakunle Oyebisi ◽  
...  
Keyword(s):  
Coarse Aggregate ◽  
Particle System ◽  
Limestone Powder ◽  
Water Quantity ◽  
Cement Particle ◽  
Fresh Properties ◽  
Self Compacting Concrete ◽  
Slump Flow ◽  
Flow Test ◽  
Bamboo Fibers

Self-compacting concrete (SCC) flows through densely steel reinforced elements and consolidates under self-weight without need for vibration or compaction. This helps in complex and densely reinforced structures. The integration of fibers and fillers in concrete improves its general properties. The addition of fibers in particular can regulate the flow and workability of the concrete; hence, the high workable nature of SCC can be an ideal mix for the incorporation of fibers. This research investigates the effect of bamboo fibers and limestone powder on the fresh properties of self-compacting concrete. Bamboo fibers of an aspect ratio of 50 and varied volumes of 0.25%, 0.5%, 0.75% and 1% were adopted for this research. The workability of the mix was assessed by slump flow test and V-funnel test. For fiber volumes of 0.25%, 0.5%, 0.75%, it was observed that the coarse aggregate was evenly distributed across the spread, indicating good viscosity and stability of the mix. The presence of 10% percent limestone powder improved the workability of the concrete mix. This can be attributed to filler properties of limestone powder, which, affecting the cement particle system, changed the ordinary distance between them and modified the water quantity available for the hydration process. These results proved that the bamboo fiber and limestone powder can be sustainably adopted to regulate the flow-ability of SCC without compromising desired properties.

Fresh Properties of Self-Compacting Concrete with Coarse Recycled Aggregate

2012 ◽  
Vol 602-604 ◽  
pp. 938-942 ◽  
Author(s):  
Wai Ching Tang
Keyword(s):  
Coarse Aggregate ◽  
Fresh Concrete ◽  
Cement Content ◽  
Recycled Aggregate ◽  
Test Results ◽  
Fresh Properties ◽  
Self Compacting Concrete ◽  
Coarse Aggregates ◽  
Filling Ability ◽  
Passing Ability

In this paper, the fresh properties of self-compacting concrete (SCC) using recycled coarse aggregate (RCA) were evaluated. Five types of SCC mixtures were made, where the percentage of substitution of natural coarse aggregate by RCA was 0, 25, 50, 75 and 100%. The cement content, water to binder (W/B) ratio and Superplasticizer dosage were kept the same for all mixes. The effects of RCA on the key fresh properties such as filling ability, passing ability, and segregation resistance of SCC were investigated by conducting several fresh concrete tests included slump-flow, L-box, and sieve stability tests. The overall test results suggest that RCA can be used to produce SCC substituting up to 100% natural coarse aggregates without affecting the key fresh properties of concrete.

scholarly journals A study of packing parameters that influence the fresh properties of self-compacting concrete

Cerâmica ◽  
2019 ◽  
Vol 65 (375) ◽  
pp. 432-442
Author(s):  
C. V. A. de Melo ◽  
P. C. C. Gomes ◽  
K. A. M. Moraes
Keyword(s):  
Distribution Coefficient ◽  
Fine Particles ◽  
The Self ◽  
Void Content ◽  
Fresh Properties ◽  
Self Compacting Concrete ◽  
Coarse Aggregates ◽  
Slump Flow ◽  
Fresh State

Abstract Some known self-compacting concrete (SCC) mix-designs are based on the lowest void content as a purpose of an ideal packing. However, a composition with a lower void content is not a guarantee of good synergy between the largest and smallest grain in the fresh state. The purpose of this study was to identify and evaluate different packing parameters in the aggregates gradations that influence on the self-compactability. Nine aggregates combinations (4 binaries, 4 ternaries and 1 quaternary) were used for determination of nine gradations. Tests as slump-flow, L-box and V-funnel were used. The distribution coefficient (q) was determined by the Alfred model. The results showed that not all values of q (between 0.201 and 0.253) attended the values given for SCC, and the gradations with the lowest difference among the coarse and fine particles, higher void content, continuous distributions and 50% of coarse aggregates had better performance.

Performance and Uniformity of Self-Compacting Concrete

2005 ◽  
Vol 1914 (1) ◽  
pp. 71-80
Author(s):  
Mohamed Nagib Abou-Zeid ◽  
Mohamed Samir Roushdy
Keyword(s):  
Coarse Aggregate ◽  
Fresh Concrete ◽  
Mechanical Vibration ◽  
Hardened Concrete ◽  
Fine Aggregate ◽  
Self Compacting Concrete ◽  
Rebound Hammer ◽  
Slump Flow ◽  
Hardened Properties ◽  
The Impact

Self-compacting concrete (SCC) can be achieved by adjusting mix proportions and incorporating adequate admixtures, such as viscosity-modifying (VM) admixtures, with no vibration. Yet, the impact of the mix proportions and the role played by the VM admixtures as opposed to those played by superplasticizer admixtures are not fully understood. There also seems to be no unique means for assessment of such concrete, and the correlation between various tests needs further work. This study aims to achieve a better understanding of the influence of mix proportions on the properties of SCC. Twenty-six mixtures were prepared with various water-to-cementitious material ratios, fine aggregate-to-coarse aggregate ratios, and admixture dosages. Fresh concrete tests, including slump flow, L-box, U-box, and hardened concrete tests, including hardened density, compressive and flexural strength, as well as the rebound hammer tests, were performed. The uniformity of SCC properties among the column specimens was examined. The results revealed that adjustment of the mix proportions has a major impact on the fresh and hardened properties of SCC. The fresh concrete tests were found to correlate well with one another, and the SCC strength was comparable to that of reference concrete made with mechanical vibration. Yet, the components of the SCC examined exhibited a remarkable uniformity of properties. Further work that should involve large specimens in which concrete properties are evaluated in various locations is needed.

scholarly journals Influence of Reduced Water Cement Ratio on Behaviour of Concrete Having Plastic Aggregate

2018 ◽  
Vol 4 (12) ◽  
pp. 2971 ◽  
Author(s):  
Saad Tayyab ◽  
Asad Ullah ◽  
Kamal Shah ◽  
Faial Mehmood ◽  
Akhtar Gul
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Stress Strain ◽  
Cement Ratio ◽  
Coarse Aggregates ◽  
Alternative Materials ◽  
Super Plasticizer ◽  
Strain Relationship ◽  
Natural Aggregates ◽  
Reduced Water

The production and use of plastic bottles is increasing tremendously with passing time. These plastic bottles become a problem when they are disposed as they are non-biodegradable. This means that the waste plastic, when dumped, does not decompose naturally and stays in the environment affecting the ecological system. The use of alternative aggregates like Plastic Coarse Aggregate (PCA) is a natural step in solving part of reduction of natural aggregates as well as to solve the issue discussed above. The researchers are trying from half a century to investigate the alternative materials to be replaced in concrete mixture in place of either aggregate or cement.  In this research, the concrete made from plastic waste as coarse aggregates were investigated for compressive strength and Stress-strain relationship. Plastic coarse aggregate have been replaced in place of natural coarse aggregate by different percentages with w/c 0.5, 0.4 and 0.3. The percentage replacement of plastic aggregate in place of mineral coarse aggregate was 25%, 30%, 35% and 40 %. Using Super-plasticizer Chemrite 520-BAS. OPC-53 grade cement was used. Total of forty five Cylinders were prepared based on different combination of Percentage of Plastic aggregate replaced and W/C as discussed above and checked for compressive strength and stress-strain relationship. The compressive strength increases by about 19.25% due to the decrease in W/C from 0.5 to 0.3 for plastic percentage addition of 40%.

Suitability of Quarry Dust as a Partial Replacement of Fine Aggregate in Self Compacting Concrete

2018 ◽  
Vol 877 ◽  
pp. 248-253
Author(s):  
Thete Swapnil Tanajirao ◽  
D. Arpitha ◽  
Suman Saha ◽  
C. Rajasekaran
Keyword(s):  
Coarse Aggregate ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Self Compacting Concrete ◽  
Slump Flow ◽  
Fine Aggregates ◽  
Material Gain ◽  
Optimum Utilization ◽  
Hardened Properties ◽  
Quarry Dust

Large quantity of the quarry dust gets produced annually in the quarries during the extraction of the crushed coarse aggregate. As a result, disposal problems of this material gain significant momentum as these disturb environmental systems also. Now-a-days many of the countries like India is facing problems of ban on the extraction of sand and lacunae in procuring of fine aggregate, which is important constituent of the concrete. To overcome this problem, present study is focused on the suitability to utilize the quarry dust in Self Compacting Concrete (SCC) partially as fine aggregate with the natural fine aggregates. In this work, quarry dust is used as replacement of sand in a different level (0%, 15%, 30%, 45% and 60%) for producing the SCC. Fresh properties such as slump flow and V-funnel time have been measured for all mixes and hardened properties as compressive strength, splitting tensile strength and flexural strength of the concrete have been checked for all the mixes and it has been found that optimum utilization of quarry dust up to 30% can been done to produce SCC without compromising with its properties.

Fresh Properties of Self-Compacting Concrete Integrating Coal Bottom Ash as a Replacement of Fine Aggregates

2015 ◽  
Vol 1125 ◽  
pp. 370-376
Author(s):  
Ahmad Farhan Hamzah ◽  
Mohd Haziman Wan Ibrahim ◽  
Norwati Jamaluddin ◽  
Ramadhansyah Putra Jaya ◽  
Norul Ernida Zainal Abidin
Keyword(s):  
Bottom Ash ◽  
Resistance Index ◽  
Ash Content ◽  
Fresh Properties ◽  
Self Compacting Concrete ◽  
Segregation Index ◽  
Coal Bottom Ash ◽  
Slump Flow ◽  
Fine Aggregates ◽  
The Stability

The influence of coal bottom ash on fresh properties of self-compacting concrete (SCC) were presented in this paper. Self-compacting concrete mixtures were produced by 0.40 water/powder ratio and coal bottom ash as a replacement of fine aggregates in varying percentages of 0%, 10%, 15%, 20%, 25% and 30%. The fresh concretes were tested for the key workability belongings of self-compacting concrete such as passing and filling abilities and segregation resistance. The fresh properties were investigated by slump flow; T500 spread time, sieve segregation and L-box test. It was found that the slump flow decreased whereas the T500 spread time increased with higher coal bottom ash content. The L-box blocking ratios changed from 0.92 to 0.65 and were mostly showed satisfactory blocking ratio. The presence of coal bottom ash improved the stability of SCC mixture and the segregation index obtained from sieve test reduced with greater bottom ash content. It can be concluding that the filling and passing ability of SCC decreased when the amount of coal bottom ash content increased. In addition, the segregation resistance index decreased with higher coal bottom ash content.

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