Engineered Cementitious Composites for Sustainable Construction

2016 ◽  
Vol 692 ◽  
pp. 17-26 ◽  
Author(s):  
S. Arundhathy ◽  
V. Vasugi
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Steel Fiber ◽  
Negative Impact ◽  
Polypropylene Fiber ◽  
Sustainable Construction ◽  
Strength Development ◽  
Compressive Strength Development ◽  
Materials Used ◽  
Ductile Behavior

Upcoming infrastructure and maintenance focuses on sustainable infrastructure. To solve this, certain cement – based materials are developed. Engineered Cementitious composite (ECC) has been developed as an improved version of Fiber Reinforced Cement. The most outstanding properties of ECC are its high tensile ductility and fine multiple cracking. It is basically a composite similar to mortar added with fine fibers such as steel fibers and polymer fibers. A composite with high ductility is made retaining the original properties of normal concrete leads to a sustainable and serviceable construction. The materials used for ECC are cement, fly ash, fine cement, admixtures, fibers and water. Sand used in this mix is very fine which have 0.1mm dia. The fibers used in this study are polypropylene and steel fiber. Fibers are added at the rate of 0.5%, 1%, 1.5%, 2% volume of cement. This paper deals with the experimental investigation of compressive strength, tensile strength, and flexural strength of ECC made with polypropylene and a mixed proportion of polypropylene with steel fiber with different volume percentages i.e., 2%, 1.5%, 1% and 0.5%. It is observed that addition of fibers increased the ductile behavior. ECC with polypropylene fiber had shown significant improvement in tensile and flexural strength while ECC with hybrid fiber had given appreciable compressive strength development. These efforts will focus on the development of sustainable green material, which reduces the negative impact of existing concrete on the environment. The potential application of ECC to achieve structural sustainability has been observed from the results obtained.

Orthogonal Experimental Study on Properties of Hybrid Fiber Reinforced Cement Mortar

2010 ◽  
Vol 168-170 ◽  
pp. 456-459
Author(s):  
Hai Yan Yuan ◽  
Shui Zhang ◽  
Guo Zhong Li
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Steel Fiber ◽  
Cement Mortar ◽  
Polypropylene Fiber ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Factors Affecting ◽  
Fiber Fraction ◽  
Reinforced Cement

By adopting the method of orthogonal experimental design, the effect of three independent variables, that is steel fiber fraction, polypropylene fiber fraction and silica fume fraction on the compressive strength, flexural strength and shrinkage of cement mortar was studied. The results indicate that steel fiber is one of the most important factors affecting compressive strength and shrinkage, and polypropylene fiber is one of the most important factors affecting flexural strength and shrinkage of cement mortar. By using deviation analysis to analyze the orthogonal experiment results, the optimized mix proportion of hybrid fiber reinforced cement mortar is determined. The hybrid effect of steel fiber and polypropylene fiber on the properties of cement mortar is discussed.

scholarly journals Compressive Strength Development of Geopolymer Mortar by Utilization Slag and Fly Ash Mixtures

2019 ◽  
Vol 9 (2) ◽  
pp. 4066-4069
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Solid Material ◽  
Solid Wastes ◽  
Strength Development ◽  
Solid Materials ◽  
Compressive Strength Development ◽  
Alkaline Activator ◽  
Materials Used ◽  
Made In

The paper displays the use of two base solid wastes materials to produce the alkaline-activated binder mortar to reduce the CO2 emission on climate change. The solid materials used in this research were slag and fly-ash to improve the compressive strength (CS) of alkaline activated mortar (AAM). The output AAM of 7 trial mixes were designed with different combinations of slag and fly ash. The mixes combinations were made in ratios of (100:0), (90:10), (80:20), (70:30), (50:50), (25:75), and (0:100), respectively. The combination of 10 M NaOH and Na2SiO3 was used as alkaline activator (AA). The wt. ratio of Na2SiO3 to NaOH = 2.5, and wt. ratio of AA to solid material = 0.52. The samples of AAM were cured at 75°C for 24 h. Among all the 7 trial mixtures, it was found that mixture with a combined ratio of slag:fly ash of 25:75 produce the maximum CS at 28 days of 88.87 MPa. Therefore, the alteration percentage of SiO2 and Al2O3 derived from fly ash in combination with CaO derived from slag contributed to significant CS improvement due to the formation of (N-A-S-H), (C-S-H) and (C-(A)-S-H) gels. The result observed of gel binder formation was confirmed by XRD and FESEM analyses.

scholarly journals Study on Steel and polypropylene hybrid fiber reinforced concrete– A review

YMER Digital ◽  
2021 ◽  
Vol 20 (11) ◽  
pp. 421-430
Author(s):  
M. Sriram ◽  
◽  
K.R. Aswin Sidhaarth ◽  
◽  
◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Steel Fiber ◽  
Polypropylene Fiber ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Hybrid Fiber ◽  
Hybrid Fibers ◽  
Split Tensile Strength

Increasing demand and inadequate materials availability leads the researchers to find alternate materials. In general, hybrid fiber is nothing but mixture of two or more fibers. In this review, various properties of steel fibers and polypropylene fibers were studied. In order to study the physical and mechanical properties of steel fiber, polypropylene fiber and other materials used in concrete, various tests such as Slump cone test, Compaction factor, Compressive strength , flexural strength etc., were used. Hybrid fibers have the tendency to control cracks at different levels. Workability of concrete get reduced due to more addition of steel fibers.The addition of steel fiber and polypropylene fiber results in an increase of 12 to 14.30% compressive strength, 33 to 36.6% increase in flexural strength and 9 to 10.16% increase in split tensile strength. Addition of most favorable amount 0.9 to 1% of steel fiber and 0.9 to 1% of polypropylene fiber gives maximum compressive strength up to 41.67 to 42.68%. Split tensile strength increases by increasing the fiber content in concrete but workability decreases when steel fiber content is increased in concrete.

scholarly journals Comparison of Long-Term Strength Development of Steel Fiber Shotcrete with Cast Concrete Based on Accelerator Type

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5599
Author(s):  
Kyong Ku Yun ◽  
Seunghak Choi ◽  
Taeho Ha ◽  
Mohammad Shakhawat Hossain ◽  
Seungyeon Han
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Steel Fiber ◽  
Strength Reduction ◽  
Strength Development ◽  
Fiber Reinforced ◽  
Cast Concrete ◽  
Long Term Performance ◽  
Term Performance

This study analyzed the effect of accelerating agents, such as aluminate, cement mineral, and alkali-free accelerators, on the long-term performance of steel-fiber-reinforced shotcrete. The shotcrete performance was studied based on the type and amount of steel fiber added. Performance tests were performed to identify the accelerator providing better long-term performance to the steel-fiber-reinforced shotcrete. Changes in strength and flexural performance over time were investigated. The compressive strength and flexural strength tests on 1-, 3-, 6-, 12-, and 24-month-old test specimens were performed, wherein 37 kg of steel fiber was added to the cement mineral and aluminate mixes, and 40 kg of steel fiber was added to the alkali-free mix. The 1-month compressive strength result of all the test variables satisfied the Korea Expressway Corporation standard. The compressive strength of the cast concrete and shotcrete specimens increased with age, demonstrating a strength reduction, particularly in the 24-month-old shotcrete specimens. Thus, the shotcrete performance may deteriorate in the long-term. In the 24-month-old specimen, substantial flexural strength reduction was observed, particularly in the aluminate and alkali-free specimens. The relative strength of the specimens was compared with that of the cast concrete mold specimens. The results suggest the use of alkali-free accelerators, considering the long-term performance of tunnels and safety of workers. Moreover, increasing the steel fiber performance rather than the amount of low-performance steel fiber must be considered.

scholarly journals Evaluation of Fiber Type and Water-Binder Ratio Influence on Concrete Properties

2019 ◽  
Vol 9 (1) ◽  
pp. 6444-6450
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Flexural Strength ◽  
Steel Fiber ◽  
Fiber Type ◽  
Linear Regression Analysis ◽  
Polypropylene Fiber ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete

This paper enumerates the experimental study on workability and strength properties of concrete containing different dosage of polypropylene fiber from 0.1% to 0.6% and 1.0% to 3.5% of steel fiber. Water - binder ratio, fiber type and fiber dosage influence on flow behaviour, compressive strength, flexural strength and brittleness ratio were analysed. Experimental results were substantiated by linear regression analysis considering 95% confidence level. Reference mixes with 0.34 and 0.36 water- binder were prepared for results comparison with polypropylene and steel fiber reinforced concretes. Test results showed comparatively higher workability reduction in polypropylene fiber reinforced concrete. Compressive strength test results of fiber reinforced concrete indicted an optimum fiber content of 0.30% of polypropylene fiber and 2.50% of steel fiber. Steel fiber reinforced concrete displayed continuous increase in flexural strength with 44.46% average increase. Brittleness ratio, which was the ratio of flexural strength and compressive strength showed maximum value of 0.24 for concrete with 3.5 % steel fiber and 0.36 w/B ratio. Linear regression analysis revealed good correlation of flow properties with w/B ratio irrespective of fiber type. Though the compressive strength had low correlation with fiber type and w/B ratio, steel fiber reinforced concrete indicated up to 0.987 coefficient of determination with flexural strength.

scholarly journals The potential use of pumice in mine backfill

2020 ◽  
Vol 1 ◽  
Author(s):  
Mohammed A. Hefni
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Mining Industry ◽  
Strength Development ◽  
Natural Pozzolan ◽  
Mine Backfill ◽  
Natural Pozzolans ◽  
Cemented Backfill ◽  
Compressive Strength Development ◽  
Potential Use

Abstract The use of natural pozzolans in concrete applications is gaining more attention because of the associated environmental, economic, and technical benefits. In this study, reference cemented mine backfill samples were prepared using Portland cement, and experimental samples were prepared by partially replacing Portland cement with 10 or 20 wt.% fly ash as a byproduct (artificial) pozzolan or pumice as a natural pozzolan. Samples were cured for 7, 14, and 28 days to investigate uniaxial compressive strength development. Backfill samples containing 10 wt.% pumice had almost a similar compressive strength as reference samples. There is strong potential for pumice to be used in cemented backfill to minimize costs, improve backfill properties, and promote the sustainability of the mining industry.

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