scholarly journals Effect of Nano Materials on Performance Characteristics of High Strength Self Compacting Concrete

NanoNEXT ◽  
2021 ◽  
pp. 26-35
Author(s):  
Boppana Narendra Kumar ◽  
Abhilash B ◽  
Naveen Kumar CH ◽  
Pavan S

In today's fast-growing world, it is critical to utilize green, sustainable, and resilient materials keeping the impact of carbon in mind. The use of Nanomaterials has evolved to improve the performance characteristics of cement composites. As a result, Graphene Oxide (G.O) was discovered to be one of the Nanomaterials with an exceptional variety of characteristics with the potential to improve the strength and toughness of cement-based composites. Nano-material concrete is a new kind of concrete composed of materials with Nano scale particle sizes. Graphene Oxide can be used in concrete to create high strength concrete. The mix design was calculated for M80 by substituting 15% cement with Fly Ash and another 15% cement with Ground Granulated Blast Furnace Slag (GGBS or GGBFS) to get High Strength Self-Compacting Concrete (HSSCC). In this paper, Graphene Oxide was added in 0%, 0.02%, 0.04%, 0.06%, 0.08% and 0.1% by weight of powder content to the Self Compacting Concrete. Fresh properties were determined by performing Slump Flow test, V-Funnel test, and L-Box test. Hardened properties were determined by conducting compression test, split tensile test and flexural test at 7 days and 28 days of age. By inclusion of Graphene Oxide to the self-compacting concrete, desired properties were achieved.

2021 ◽  
Vol 7 (8) ◽  
pp. 1426-1436
Author(s):  
Mujahid Hussain Lashari ◽  
Noor Ahmed Memon ◽  
Muneeb Ayoub Memon

The self-compacted concrete (SCC) is a special type of concrete which settles down in the formwork and fills its every corner without any use of compaction or vibration. As SCC has higher flow-ability that causes brittle behaviour resulting in poor performance under tension and bending. The inclusion of randomly distributed short and discrete fibers is one of the most effective way to improve the tensile as well as flexural performance of SCC. In this regard this experimental study is undertaken to investigate the effect of nylon fibers (NF) on fresh and hardened properties of SCC. Two different lengths; 20 mm and 12 mm and five different volumetric percentages; 0.1, 0.2, 0.3, 0.4 and 0.5% of NF were used. The results revealed that addition of NF slightly affects the fresh properties of SCC. However, the extent of the effect is not of that order to be considered as major factor. The fresh properties for entire mixes lie within the required range according to EFNARC guidelines. The strength properties increases with addition of NF, the extent of increment is greater for the longer length of NF. The optimum volumetric fraction of NF for producing high strength SCC was found as 0.5%. Doi: 10.28991/cej-2021-03091734 Full Text: PDF


Concrete having characteristics strength of more than 65 MPa is categorized as high-strength concrete according to IS 456. The high strength concrete is more brittle compared to ordinary strength concrete and inclusion of fibers can increase the ductility of concrete. In the present study, high strength self-compacting concrete of characteristic strength of 90 MPa was developed as per the guidelines of EFNARC. Basalt fibers were considered to investigate its influence on the properties of high strength self compacting concrete. Three aspect ratios of 230, 530 and 600 were considered and are added in proportions of 0.1% and 0.4% by volume of concrete. The properties of concrete determine were fresh and hardened. Fresh properties such as slump flow test, V-funnel test, V-funnel T5 minutes and L-box test were determined as per EFNARC. Also, hardened properties such as compressive strength, split tensile strength and flexural strength were determined. A typical comparison on the effect of aspect ratio of basalt fibers and the dosage on the properties of concrete were determined. From the results, the optimum dosage of fibers was determined.


2020 ◽  
Vol 10 (23) ◽  
pp. 8543
Author(s):  
Mosbeh R. Kaloop ◽  
Pijush Samui ◽  
Mohamed Shafeek ◽  
Jong Wan Hu

The characteristics of fresh and hardened self-compacting concrete (SCC) are an essential requirement for construction projects. Moreover, the sensitivity of admixture contents of SCC in these properties is highly impacted by that cost. The current study investigates to estimate the slump-flow (S) and compressive strength (CS), as fresh and hardened properties of SCC, respectively. Four developed soft-computing approaches were proposed and compared, including the group method of data handling (GMDH), Minimax Probability Machine Regression (MPMR), emotional neural network (ENN), and hybrid artificial neural network-particle swarm optimization (ANN-PSO), to estimate the S and 28-day CS of SCC, which comprises fly ash (FA), silica fume (SF), and limestone powder (LP) as part of cement by mass in total powder content. In addition, the impact of eight admixture components is investigated and evaluated to assess the sensitivity of admixture contents for the modelling of S and CS of SCC. The results demonstrate that the performance prediction of ENN model is more significant than other models in estimating S and CS characteristics of SCC. The overall of Pearson correlation coefficient, r, and root mean square error (RMSE) of ENN model are 97.80% and 20.16 mm, respectively, for the S. These are 96.07% and 2.59 MPa, respectively, for the CS. Furthermore, the sensitivity of the powder content of fly ash is shown to have a high impact on the estimated S and CS values of SCC.


Author(s):  
Chikluru Arifa ◽  
K. Mohammed Rasheed ◽  
C. Ramachandrudu

Civil engineering is a professional engineering discipline that deals with the designing and construction. In construction one of the main resource is concrete in the world. The concrete is day-to-day have many changes like strength, durability, shrinkage. This project deals with the self-compaction concrete with use of fibre reinforcement. The self-compacting in concrete is achieved by adding super plasticizers and glass fibres are used as reinforcement. The influence of including fly ash on the properties of self-compacting concrete is investigated. Fly ash is introduced by 50% in the total weight of cement. The water to binder ratio was maintained at 0.38%. Properties included workability, compressive strength, split tensile test, modulus of elasticity and shrinkage. The results indicate the high volume FA can be used in SCC to produce the high strength and low shrinkage. Increasing the admixture content beyond the certain level leads to a reduction in strength and increasing in absorption. Making concrete structure without compaction has been done in the past. Like placement of concrete under water by the use of term without compaction. Inaccessible areas were concrete using such a techniques. The production of such mixes use expensive admixtures ad large amount of cement but such type of concrete is low strength. To eliminate such issues lead to the development of self-compacting concrete (SCC). Usage of fibres makes the mixing of concrete complex. Self-compacting concrete (SCC) is an innovative concrete that does not require vibration for placing and compaction.


Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 91
Author(s):  
Sallal R. Abid ◽  
Murali Gunasekaran ◽  
Sajjad H. Ali ◽  
Ahmed L. Kadhum ◽  
Thaar S. Al-Gasham ◽  
...  

The self-compacting concrete (SCC) was invented to overcome the compaction problems in deep sections, owing to its perfect workability characteristics. Steel fibers when used with SCC would affect the required fluidity characteristics but improve its impact resistance. In this research, an experimental work was conducted to evaluate the impact response of micro-steel fiber-reinforced SCC, under flexural impact. A 5.47 kg free-falling mass was dropped repeatedly from 100 mm height on the top center of 270 mm-length beam specimens. Eight mixtures with two design grades of 30 and 50 MPa were prepared to distinguish the normal and high-strength SCCs. The distinguishing variable for each design grade was the fiber content, where four volumetric contents of 0%, 0.5%, 0.75%, and 1.0% were used. The test results showed that the impact resistance and ductility were significantly improved due to the incorporation of micro-steel fibers. The percentage improvements were noticeably higher at failure stage than at cracking stage. For the 30 MPa mixtures, the maximum percentage improvements at cracking and failure stages were 543% and 836%, respectively. Weibull’s linear correlations with R2 values of 0.84 to 0.97 were obtained at the failure stage, which meant that the impact failure number followed the Wiebull distribution.


2018 ◽  
Vol 7 (3.35) ◽  
pp. 52
Author(s):  
S Shrihari ◽  
M V Seshagiri Rao ◽  
V Srinivasa Reddy ◽  
Venkat Sai

The quest for the development of high strength and high performance concretes has increased considerably in recent times because of the demands from the construction industry. High-performance concretes can be produced at lower water/powder ratios by incorporating these supplementary materials. Fly ash addition proves most economical among these choices, even though addition of fly ash may lead to slower concrete hardening. However, when high strength is desired, use of silica fume is more useful. This paper proposes a mix proportions for M80 grade Self-compacting concrete (SCC) based on Nan Su mix design principles. First, the amount of aggregates required is determined, and the paste of binders is then filled into the voids of aggregates to ensure that the concrete thus obtained has flowability, self-compacting ability and other desired SCC properties. The amount of aggregates, binders and mixing water, as well as type and dosage of superplasticizer (SP) to be used are the major factors influencing the properties of SCC. Slump flow, V-funnel, L-flow, U-box and compressive strength tests were carried out to examine the performance of SCC, and the results indicate that the Nan Su method could produce successfully SCC of high strength. Based on Nan Su mix design method, material quantities such as powder content ( Cement + Pozzolan ), fine aggregate, coarse aggregate, water and dosages of SP and VMA,  required for 1 cu.m,  are evaluated for High strength grade (M80) of Self Compacting Concrete (SCC) are estimated. Final quantities, of M80 grade SCC mix, is assumed after several trial mixes on material quantities computed using Nan Su mix design method subjected to satisfaction of EFNARC flow properties. 


Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5506
Author(s):  
Mohammed A. Abed ◽  
Jan Fořt ◽  
Abdulkarim Naoulo ◽  
Amr Essa

The research reported in this paper aims to evaluate the epoxy injection technique used to strengthen fiber-reinforced self-compacting concrete (FRSCC) with high strength. This method is carried out on ruptured concrete specimens to assess the efficiency of the epoxy resin adhesive injection retrofitting technique for strength and stiffness. Five FRSCC mixes were designed and placed using different types (steel and polypropylene) and contents (0%, 0.25%, and 0.45% by volume) of fibers. The fresh and mechanical properties in addition to the microstructure of produced mixes were evaluated to assess the impact of fibers on the behavior of FRSCC. Results showed that the workability of FRSCC is reduced by increasing steel or polypropylene fiber content; however, the rheological characteristics of placed mixes satisfied the European Guidelines for Self-Compacting Concrete recommendation for fresh concrete. Also, splitting tensile, flexural, and shear strengths were enhanced by increasing fiber content. The simultaneous application of epoxy injection in FRSCC for repairing damaged concrete beams was shown to be highly effective.


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