Performance of very-high-strength concrete subjected to short-term repeated loading

This paper describes the potential suitability of a new family of concrete mixtures for use in protective structures. Two very-high-strength concrete mixtures are discussed and experimental results of penetration studies on one of these are presented. The results are compared to penetration-study results of other, more conventional concrete mixtures, and the advantages of the very-high-strength mixtures are described.

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Behavior of High Strength Hybrid Reinforced Concrete Deep Beams under Monotonic and Repeated Loading

The Open Civil Engineering Journal ◽

10.2174/1874149501812010263 ◽

2018 ◽

Vol 12 (1) ◽

pp. 263-282 ◽

Cited By ~ 2

Author(s):

Sawsan Akram Hassan ◽

Ansam Hassan Mhebs

Keyword(s):

High Strength Concrete ◽

Ultimate Load ◽

High Strength ◽

Monotonic Loading ◽

Repeated Loading ◽

Percentage Increase ◽

Deep Beams ◽

Strength Concrete ◽

Hybrid Beam ◽

Web Reinforcement

Introduction:This study presents the experimental and analytical investigation of the behavior of high strength hybrid reinforced concrete deep beams under monotonic and repeated two-point load. The idea of hybrid in this work is different. Two types of concrete were used in beam but not in cross-section. The first type was the Fibrous High Strength Concrete (FHSC) at shear spans for enhancing shear capacity against cracking due to diagonal strut failure (by adding Steel Fiber (SF) in that regions), while the second type was the Conventional High Strength Concrete (CHSC) at the mid-portion between the two strengthened shear spans.Methods:The experimental work included the casting and testing of ten deep beams. Five among the beams were tested under monotonic loading (control beams) and other beams were tested under repeated loading at the level of 75% of ultimate load of control beams. The effect of some selected parameters as the type of load, the hybrid and non-hybrid beams, the compressive strength of concrete (fʹc) (normal and high) and the amount of web reinforcement (ρw) were studied in terms of crack patterns, ultimate load and load versus midspan deflection.Results and Conclusion:From the experimental test results, when beam cast with fibrous with SF of 1% concrete along entire length, the ultimate load of 10.96% increased as compared with hybrid beam. And it was observed to increase as much as 32.78% as compared with beam cast from conventional high strength concrete under monotonic loading. Under repeated loading of 75% control ultimate load, the ultimate load for beam cast with fibrous concrete along entire length increased as much as 15.32% as compared with hybrid beam. And it was seen to increase 36.17% as compared with the beam cast from conventional high strength concrete. The percentage increase in ultimate load of hybrid (SF ratio 1%) deep beam cast with high strength concrete became 97.3% as compared with the identical beam cast with normal strength concrete under monotonic loading and (98.21%) under repeated loading (load 75% control beam load). The percentage increase as ultimate load for hybrid beam cast with SF ratio 1% was 9.62% as compared with hybrid beam with SF ratio 0%. As the web reinforcement increased from 0 to 0.004 and from 0 to 0.006, the percentage increased in the ultimate load as 28.07% and 57.89%, under monotonic loading as 26.14% and 59.09%, under repeated loading.Then, Strut and Tie model (STM) procedures were used to analyze the experimentally tested hybrid deep beams under monotonic loading of the present investigation. Comparison of experimental results was made with corresponding predicted values using the STM procedure presented of ACI 318R-14 Code and with other procedures

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Aggregate-Dependent Approach to Formulate and Predict Properties of High-Strength and Very-High-Strength Concrete

Journal of Materials in Civil Engineering ◽

10.1061/(asce)mt.1943-5533.0003055 ◽

2020 ◽

Vol 32 (4) ◽

pp. 04020053 ◽

Cited By ~ 2

Author(s):

Shanaka Kristombu Baduge ◽

Priyan Mendis ◽

Rackel San Nicolas ◽

Maduwanthi Rupasinghe ◽

Joanne Portella

Keyword(s):

High Strength Concrete ◽

High Strength ◽

Strength Concrete ◽

Very High

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L'utilisation des bétons à très haute résistance au Canada

Canadian Journal of Civil Engineering ◽

10.1139/l89-099 ◽

1989 ◽

Vol 16 (5) ◽

pp. 661-668

Author(s):

Pierre Laplante ◽

Pierre-Claude Aïtcin

Keyword(s):

Compressive Strength ◽

North America ◽

High Strength Concrete ◽

High Strength ◽

Cement Ratio ◽

Strength Concrete ◽

Chicago Area ◽

New Type ◽

Ready Mixed Concrete ◽

Very High

In the late sixties, several concrete producers in the Chicago area developed very high strength concrete. The compressive strength of this new type of concrete was increased gradually, and it is now possible to buy 100 MPa ready-mixed concrete in several places in North America. Of significant technological importance, very high strength concrete is becoming popular all over North America due to its profitability. As to why and how very high strength concrete is made, the readily available answers to the first question contrast with the predominately empirical approach that has characterized research into producing very high strength concrete up to now. In fact, there are no miracle mixes that will universally guarantee the availability of 100 MPa ready-to-use concretes. Nonetheless, some guidelines have been established that should be followed in order to avoid various pitfalls. In Canada, very high strength concrete is beginning to be used in the Toronto and Montreal areas. This paper summarizes the principal results obtained on two specific projects: the construction of an experimental column in Montreal in 1984, and the construction of Nova Scotia Plaza in Toronto in 1986. Key words: high-strength concrete, water/cement ratio, superplasticizer, silica fume, slag.

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