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.

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 Kajian Karakteristik Beton Memadat Sendiri yang Menggunakan Serat Ijuk (Hal. 54-65)

2018 ◽  
Vol 4 (4) ◽  
pp. 54
Author(s):  
Iis Nurjamilah ◽  
Abinhot Sihotang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Coarse Aggregate ◽  
Fresh Concrete ◽  
High Strength ◽  
Self Compacting Concrete ◽  
Palm Fiber ◽  
Fiber Concrete ◽  
Dilute Mixture

ABSTRAKKajian karakteristik beton memadat sendiri yang menggunakan serat ijuk merupakan sebuah kajian yang dilakukan untuk mengetahui pengaruh penambahan serat ijuk terhadap karakteristik beton memadat sendiri (SCC). Beton memadat sendiri yang menggunakan serat ijuk (PFSCC) didesain memiliki campuran yang encer, bermutu tinggi (= 40 MPa) dan memiliki persentase kekuatan lentur yang lebih baik. PFSCC  didapatkan dari hasil pencampuran antara semen sebanyak 85%, fly ash 15%, superplastizicer 1,5%, serat ijuk 0%, 0,5%; 1%; 1,5%; 2% dan 3% dari berat binder (semen + fly ash), kadar air 190 kg/m3, agregat kasar 552,47 kg/m3 dan pasir 1.063 kg/m3. Semakin banyak persentase penambahan serat ijuk ke dalam campuran berdampak terhadap menurunnya workability beton segar. Penambahan serat ijuk yang paling baik adalah sebanyak 1%, penambahan tersebut dapat meningkatkan kekuatan tekan beton sebesar 13% dan lentur sebesar 1,8%.Kata kunci: beton memadat sendiri (SCC), beton berserat, beton memadat sendiri yang menggunakan serat ijuk (PFSCC), serat ijuk ABSTRACTThe study of characteristics self compacting concrete using palm fibers is a study conducted to determine the effect of adding palm fibers to characteristics of self compacting concrete (SCC). palm fibers self compacting concrete (PFSCC) is designed to have a dilute mixture, high strength (= 40 MPa), and have better precentage flexural strength. PFSCC was obtained from mixing of 85% cement, 15% fly ash, 1.5% superplastizicer, 0%, 0.5%, 1%, 1.5%, 2% and 3% palm fibers from the weight of binder  (cement + fly ash), water content 190 kg/m3, coarse aggregate 552.47 kg/m3 and sand 1,063 kg/m3. The more persentage palm fibers content added to the mixture makes workability of fresh concrete decreases. The best addition of palm fiber is 1%, this addition can increases the compressive strength 13% and flexural strength 1.8%.Keywords: self compacting concrete (SCC), fiber concrete, Palm fiber self compacting concrete (PFSCC), palm fiber

Fresh, Durability and Mechanical Behavior of Self Consolidating Concrete Incorporating Fly Ash and Admixture under Hot Weather

2021 ◽  
Vol 904 ◽  
pp. 453-457
Author(s):  
Samer Al Martini ◽  
Reem Sabouni ◽  
Abdel Rahman Magdy El-Sheikh
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Water Absorption ◽  
Weather Conditions ◽  
Chloride Penetration ◽  
The Self ◽  
Fresh Properties ◽  
Self Consolidating Concrete ◽  
Slump Flow ◽  
Hot Weather

The self-consolidating concrete (SCC) become the material of choice by concrete industry due to its superior properties. However, these properties need to be verified under hot weather conditions. The paper investigates the behavior of SCC under hot weather. Six SCC mixtures were prepared under high temperatures. The SCC mixtures incorporated polycarboxylate admixture at different dosages and prolonged mixed for up to 2 hours at 30 °C and 40 °C. The cement paste was replaced with 20% of fly ash (FA). The fresh properties were investigated using slump flow, T50, and VSI tests. The compressive strength was measured at 3, 7, and 28 days. The durability of SCC mixtures was evaluated by conducting rapid chloride penetration and water absorption tests.

scholarly journals Acidic solution effects on no-fines concrete produced by using recycled concrete as coarse aggregate

2018 ◽  
Vol 162 ◽  
pp. 02002
Author(s):  
Ikbal Gorgis ◽  
Whab Faleh Abd ◽  
Shaker Al-Mishhadani
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Maximum Size ◽  
Recycled Concrete ◽  
Type I ◽  
Coarse Aggregates ◽  
Crushed Concrete ◽  
Compaction Factor ◽  
Single Size ◽  
Better Than

This paper investigates durability of no fine concrete containing demolished concrete as coarse aggregate after crushing to different sizes. Different no fine concrete mixes were considered using Portland cement type I with two types of coarse aggregates, crushed demolished concrete and crushed natural gravel were used with two ratios by weight (1:5 and 1:7) C/Agg. Graded aggregate and single size were used with a maximum size of 20 mm. W /C ratio was kept as 0.4 for all mixes and super-plasticizer was required to keep the same flow and compaction factor value for all mixes. Cube specimens with 150mm were cured and divided to two parts, the first part was exposed to 60 cycles of freezing- thawing; the second part of the sample was immersed in Nitric Acids solution with pH of 3.5 for (7, 28, 90 and 180 days) and then tested for compressive strength. The results indicated that it is possible to produce homogenous and workable mixes by using demolished crushed concrete as coarse aggregate. The compressive strength after cycles of freezing- thawing and immersing in Nitric acid (HNO3) at (7, 28, 90 and 180) days was decreased for samples made with crushed demolished concrete. Also it is found that the performance of concrete mixes containing graded coarse aggregate and 1:5 cement/aggregate ratios was better than other mixes.

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.

scholarly journals Effect of recycled coarse aggregate on the properties of C40 self-compacting concrete

2019 ◽  
Vol 28 ◽  
pp. 096369351988512 ◽  
Author(s):  
Yunyang Wang ◽  
Bingchen Zhao ◽  
Guang Yang ◽  
Yandong Jia ◽  
Lijun Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Coarse Aggregate ◽  
Lower Amount ◽  
Theoretical Formula ◽  
Self Compacting Concrete ◽  
Recycled Coarse Aggregate ◽  
Slump Flow ◽  
Experimental Values

The effect of recycled coarse aggregate (RCA) on the fresh and hardened properties of C40 self-compacting concrete (SCC) was investigated in this paper. The slump, T 500 (the time needed for SCC to spread into a round configuration with a nominal diameter of 500 mm), the slump flow and the flow time of fresh C40 SCC as well as the compressive strength and modulus of elasticity of hardened C40 SCC were studied. The modulus of elasticity of C40 SCC was calculated by theoretical formula, and the calculated values were compared with the experimental values. Mechanisms that effect on the C40 SCC properties at fresh and hardened states were also explored. The experimental results showed that the slump values of the C40 SCC are beyond 250 mm. The C40 SCC with RCA replacement content of 50% showed the highest slump value of 275 mm. All T 500 values of the C40 SCC are within 5 s. The slump flow of the C40 SCC slightly increases with the increase of replacement content of the RCA. In contrast, the compressive strength and modulus of elasticity of the C40 SCC slightly decrease with the increase of replacement content. The experimental values of modulus of elasticity are lower than that of the calculated values. Submerged in water before mixing of RCA leading to the slump flow of the C40 SCC increases with the increasing replacement content of the RCA. The old cement mortar attached to the RCA surface is the main reason that weakens the mechanical properties. The lower amount of coarse aggregate and the higher amount of cement paste attribute to the lower values of modulus of elasticity. This study implied that RCA can be effectively used in the production of C40 SCC without any significant sacrifice on workability and mechanical 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.

Research on Self-Compacting Concrete Made with Recycled Aggregate

2013 ◽  
Vol 639-640 ◽  
pp. 399-403
Author(s):  
Ai Guo Zhou ◽  
Jian Yin ◽  
Wei Min Song ◽  
Yi Chi
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Coarse Aggregate ◽  
Recycled Aggregate ◽  
Self Compacting Concrete ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates ◽  
Mineral Additive ◽  
Binder Ratio ◽  
Water Binder Ratio

It is studied the effect of binder quantity, water binder ratio on properties of self-compacting concrete made with recycled coarse aggregates. It can be prepared C50 self-compacting concrete made with recycled coarse aggregate by adjusting send proportion, binder quantity, and mixing mineral additive. For example, when the binder quantity is 600 kg/m3, water binder ratio is 0.28, the flexural strength and compressive strength at 28 days of self-compacting concrete made with recycled coarse aggregates are 9.07 MPa and 68.47 MPa respectively.

scholarly journals Influence of Granite Cutting Waste and Recycled Concrete on Properties of Self Compacting Concrete

2019 ◽  
Vol 8 (4) ◽  
pp. 205-208
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Strength Test ◽  
Recycled Concrete ◽  
Fine Aggregate ◽  
Self Compacting Concrete ◽  
Slump Flow ◽  
Hardened Properties ◽  
Passing Ability

This paper explains the combined effect of granite cutting waste and recycled concrete on the workability and mechanical properties of self compacting concrete. Experimental plan is divided in such a way that granite cutting waste is replaced with fine aggregate at 0, 20,40,60,80 and 100% proportions. Recycled concrete is replaced with the coarse aggregate starting from 20 to 100%. Total 36 mixes were designed to check the fresh and hardened properties. Slump flow and T500, v-funnel and L-box test are conducted to know the flow ability and passing ability of concrete. To study the hardened properties compressive strength, flexural strength test values are to be collected.

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