Comparative Study of Strength-based Damage Evolution in Ultra-High-Performance Concrete (UHPC) and Conventional Concrete (CC) under dynamic loading

Author(s):  
Qiran Sun ◽  
Brett Williams ◽  
Colin Loeffler ◽  
Bradley Martin ◽  
William Heard ◽  
...  
Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2455
Author(s):  
Jiayuan He ◽  
Weizhen Chen ◽  
Boshan Zhang ◽  
Jiangjiang Yu ◽  
Hang Liu

Due to the sharp and corrosion-prone features of steel fibers, there is a demand for ultra-high-performance concrete (UHPC) reinforced with nonmetallic fibers. In this paper, glass fiber (GF) and the high-performance polypropylene (HPP) fiber were selected to prepare UHPC, and the effects of different fibers on the compressive, tensile and bending properties of UHPC were investigated, experimentally and numerically. Then, the damage evolution of UHPC was further studied numerically, adopting the concrete damaged plasticity (CDP) model. The difference between the simulation values and experimental values was within 5.0%, verifying the reliability of the numerical model. The results indicate that 2.0% fiber content in UHPC provides better mechanical properties. In addition, the glass fiber was more significant in strengthening the effect. Compared with HPP-UHPC, the compressive, tensile and flexural strength of GF-UHPC increased by about 20%, 30% and 40%, respectively. However, the flexural toughness indexes I5, I10 and I20 of HPP-UHPC were about 1.2, 2.0 and 3.8 times those of GF-UHPC, respectively, showing that the toughening effect of the HPP fiber is better.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4304
Author(s):  
Markssuel Teixeira Marvila ◽  
Afonso Rangel Garcez de de Azevedo ◽  
Paulo R. de de Matos ◽  
Sergio Neves Monteiro ◽  
Carlos Maurício Fontes Vieira

This review article proposes the identification and basic concepts of materials that might be used for the production of high-performance concrete (HPC) and ultra-high-performance concrete (UHPC). Although other reviews have addressed this topic, the present work differs by presenting relevant aspects on possible materials applied in the production of HPC and UHPC. The main innovation of this review article is to identify the perspectives for new materials that can be considered in the production of novel special concretes. After consulting different bibliographic databases, some information related to ordinary Portland cement (OPC), mineral additions, aggregates, and chemical additives used for the production of HPC and UHPC were highlighted. Relevant information on the application of synthetic and natural fibers is also highlighted in association with a cement matrix of HPC and UHPC, forming composites with properties superior to conventional concrete used in civil construction. The article also presents some relevant characteristics for the application of HPC and UHPC produced with alkali-activated cement, an alternative binder to OPC produced through the reaction between two essential components: precursors and activators. Some information about the main types of precursors, subdivided into materials rich in aluminosilicates and rich in calcium, were also highlighted. Finally, suggestions for future work related to the application of HPC and UHPC are highlighted, guiding future research on this topic.


DYNA ◽  
2021 ◽  
Vol 88 (216) ◽  
pp. 38-47
Author(s):  
Joaquín Abellán García ◽  
Nancy Torres Castellanos ◽  
Jaime Antonio Fernandez Gomez ◽  
Andres Mauricio Nuñez Lopez

Ultra-high-performance concrete (UHPC) is a kind of high-tech cementitious material with superb mechanical and durability properties compared to other types of concrete. However, due to the high content of cement and silica fume used, the cost and environmental impact of UHPC is considerably higher than conventional concrete. For this reason, several efforts around the world have been made to develop UHPC with greener and less expensive local pozzolans. This study aimed to design and produce UHPC using local fly ash available in Colombia. A numerical optimization, based on Design of Experiments (DoE) and multi-objective criteria, was performed to obtain a mixture with the proper flow and highest compressive strength, while simultaneously having the minimum content of cement. The results showed that, despite the low quality of local fly ashes in Colombia, compressive strength values of 150 MPa without any heat treatment can be achieved.


2018 ◽  
Vol 149 ◽  
pp. 01005 ◽  
Author(s):  
Arezki Tagnit-Hamou ◽  
Ablam Zidol ◽  
Nancy Soliman ◽  
Joris Deschamps ◽  
Ahmed Omran

Ground-glass pozzolan (G) obtained by grinding the mixed-waste glass to same fineness of cement can act as a supplementary-cementitious material (SCM), given that it is an amorphous and a pozzolanic material. The G showed promising performances in different concrete types such as conventional concrete (CC), high-performance concrete (HPC), and ultra-high performance concrete (UHPC). The current paper reports on the characteristics and performance of G in these concrete types. The use of G provides several advantages (technological, economical, and environmental). It reduces the production cost of concrete and decrease the carbon footprint of a traditional concrete structures. The rheology of fresh concrete can be improved due to the replacement of cement by non-absorptive glass particles. Strength and rigidity improvements in the concrete containing G are due to the fact that glass particles act as inclusions having a very high strength and elastic modulus that have a strengthening effect on the overall hardened matrix.


2017 ◽  
Vol 3 (3) ◽  
pp. 190-198 ◽  
Author(s):  
Mohamadtaqi Baqersad ◽  
Ehsan Amir Sayyafi ◽  
Hamid Mortazavi Bak

During the past decades, there has been an extensive attention in using Ultra-High Performance Concrete (UHPC) in the buildings and infrastructures construction. Due to that, defining comprehensive mechanical properties of UHPC required to design structural members is worthwhile. The main difference of UHPC with the conventional concrete is the very high strength of UHPC, resulting designing elements with less weight and smaller sizes.  However, there have been no globally accepted UHPC properties to be implemented in the designing process. Therefore, in the current study, the UHPC mechanical properties such as compressive and tensile strength, modulus of elasticity and development length for designing purposes are provided based on the reviewed literature. According to that, the best-recommended properties of UHPC that can be used in designing of UHPC members are summarized. Finally, different topics for future works and researches on UHPC’s mechanical properties are suggested.


2020 ◽  
Vol 16 (1) ◽  
pp. 26-35
Author(s):  
Carlos Eduardo Tino Balestra ◽  
Jennifer Stephane Ozelame ◽  
Gustavo Savaris

RESUMO: A exigência de materiais com desempenho superior aos utilizados usualmente na construção civil impulsiona pesquisas que visam o desenvolvimento de novas tecnologias. Neste contexto, surgem os concretos de ultra alto desempenho reforçados com fibras (UHPFRC), que se destacam pelas elevadas resistências à compressão e à tração e maior ductilidade em relação a um concreto convencional. O presente trabalho teve como objetivo principal avaliar experimentalmente a resistência à compressão e comportamento pós ruptura de UHPFRC com diferentes tipos e dosagens de fibras, utilizando materiais disponíveis no mercado brasileiro, visando o emprego deste material nos processos construtivos atuais. A partir de um traço de concreto de ultra alto desempenho foram definidas misturas de UHPFRC com fibras de aço e de fibras de polietileno utilizando volumes de 0,5% e 1% de fibras. Os resultados obtidos foram comparados a um concreto de referência sem fibras, demonstrando que as fibras melhoram a ductilidade do concreto e provém uma resistência residual ao mesmo, sendo observados, após sua fratura, picos de recuperação graças à melhor aderência das fibras ao concreto. Além disso, para ambas as fibras, uma maior quantidade de fibras auxiliou a combater as rupturas bruscas observadas após concretos sem fibras esgotarem sua capacidade resistente. ABSTRACT: The demand for materials with higher performance than those usually used in civil construction stimulate researches aimed at the development of new technologies. In this context, ultra high performance fibers reinforced concrete (UHPFRC) stands out due to the high compressive and tensile strengths and higher ductility compared to conventional concrete. The present work had as main objective to evaluate experimentally the compressive strength and post - rupture behavior of UHPFRC with different types and dosages of fibers, using materials available in Brazil, aiming the use of these material in the current constructive processes. UHPFRC mixtures with steel fibers and polyethylene fibers using 0.5% and 1% fiber volumes were defined from an ultra high performance concrete mixture. The results obtained were compared to a reference concrete without fibers, demonstrating that the fibers improve the ductility of the concrete and provide a residual resistance after the exemplar fracture, recovery peaks due to the better adhesion of the fibers to the concrete. In addition, for both fibers, a greater amount of fibers helped to avoid sudden ruptures observed after concrete without fibers reached their resistant capacity.


2021 ◽  
Author(s):  
Jedadiah Burroughs ◽  
Jason Weiss ◽  
John Haddock

Specialized classes of concrete, such as ultra-high-performance concrete, use volumes of silica fume in concrete that are higher than those in conventional concrete, resulting in increased water demand and mixing difficulty. This study considered the effects of eight different silica fumes in three dosages (10%, 20%, 30%) with three w/b (0.20, 0.30, 0.45) on rheological behavior as characterized by the Herschel-Bulkley model. Results indicated that the specific source of silica fume used, in addition to dosage and w/b, had a significant effect on the rheological behavior. As such, all silica fumes cannot be treated as equivalent or be directly substituted one for another without modification of the mixture proportion. The rheology of cement pastes is significantly affected by the physical properties of silica fume more so than any chemical effects.


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