scholarly journals Partial Replacement of Cement with Combination of Alccofine and Marble Dust for Development of Sustainable Concrete

2019 ◽  
Vol 8 (4) ◽  
pp. 1190-1194

Concrete is second most consumed material in the world after water. Cement being the important material of concrete needs to be manufactured in large amount. Production of cement involves large amount of carbon dioxide emissions into the atmosphere, a major contributor for greenhouse effect and global warming. Also demand of high performance concrete (HPC) for infrastructural industry is growing. Thus, it becomes necessary to discover a partial replacement of material for cement in concrete which is environmental friendly and strength gaining which solves both issues. Leaving the waste materials to the environment directly can also cause environmental problem. Marble Dust Powder (MDP) is a developing composite material that will allow the concrete industry to optimize materiel use, generate economic benefits. Alccofine is a new generation ultra fine supplementary cementetious material as a partial replacement of cement. It also tends to gain high performance of concrete. Usage of alccofine and MDP in a combination as supplementary cementetious material (SCM) by partially replacing cement in concrete can be a leading step towards sustainable development of concrete industry. Comparing and examining the physical properties of this new modified concrete with conventional concrete is the motivation of this study.

2014 ◽  
Vol 911 ◽  
pp. 479-483 ◽  
Author(s):  
Samir Bouhedja ◽  
Boualem El Kechebour ◽  
Ahmed Boukhaled

The objective of this work is an analysis of the use of high performance concrete and it impact on the morphology and structure costs. The use of high performance concrete (HPC) in the construction of buildings and civil engineering works offers advantages in terms of durability, ease of implementation, reduction of deformation and shrinkage, increase the resistance of reinforced concrete structures. The economic benefits of the use of high performance concrete, compared to conventional concrete are illustrated by the reduction of the following costs: the implementation of concrete, the geometric sections of bearing elements of the built space and the maintenance of structures. The cost of high performance concrete, for the resistance inferior to 80 Mpa, gives a significative advantage comparatively to the steel and the ordinary concrete. The generalized use of this type of concrete in many countries has been stimulated by a national plan.


2020 ◽  
Vol 838 ◽  
pp. 88-93
Author(s):  
Kristýna Hrabová

Green concrete is defined as a concrete which uses waste material as at least one of its components, or its production process does not lead to environmental destruction, or it has high performance and life cycle sustainability. Currently, cement and concrete production is at all-time high resulting in significant carbon dioxide emissions. Eight percent of the world's total CO2 emissions come from manufacturing cement. Nanomaterial concrete is new generation concrete formed of materials of the grain size of nanoscale. In the construction industry, nanomaterials has potentials, especially the functional characteristics such as increased tensile strength. The paper shows the dose dependence carbon nanotubes for the physico-mechanical properties of cement mixes.


Author(s):  
Ariful Hasnat ◽  
Nader Ghafoori

AbstractThis study aimed to determine the abrasion resistance of ultra-high-performance concretes (UHPCs) for railway sleepers. Test samples were made with different cementitious material combinations and varying steel fiber contents and shapes, using conventional fine aggregate. A total of 25 UHPCs and two high-strength concretes (HSCs) were selected to evaluate their depth of wear and bulk properties. The results of the coefficient of variation (CV), relative gain in abrasion, and abrasion index of the studied UHPCs were also obtained and discussed. Furthermore, a comparison was made on the resistance to wear of the selected UHPCs with those of the HSCs typically used for prestressed concrete sleepers. The outcomes of this study revealed that UHPCs displayed excellent resistance against abrasion, well above that of HSCs. Amongst the utilized cementitious material combinations, UHPCs made with silica fume as a partial replacement of cement performed best against abrasion, whereas mixtures containing fly ash showed the highest depth of wear. The addition of steel fibers had a more positive influence on the abrasion resistance than it did on compressive strength of the studied UHPCs.


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.


Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 427
Author(s):  
Pavlina Mateckova ◽  
Vlastimil Bilek ◽  
Oldrich Sucharda

High-performance concrete (HPC) is subjected to wide attention in current research. Many research tasks are focused on laboratory testing of concrete mechanical properties with specific raw materials, where a mixture is prepared in a relatively small amount in ideal conditions. The wider utilization of HPC is connected, among other things, with its utilization in the construction industry. The paper presents two variants of HPC which were developed by modification of ordinary concrete used by a precast company for pretensioned bridge beams. The presented variants were produced in industrial conditions using common raw materials. Testing and comparison of basic mechanical properties are complemented with specialized tests of the resistance to chloride penetration. Tentative expenses for normal strength concrete (NSC) and HPC are compared. The research program was accomplished with a loading test of model experimental pretensioned beams with a length of 7 m made of ordinarily used concrete and one variant of HPC. The aim of the loading test was to determine the load–deformation diagrams and verify the design code load capacity calculation method. Overall, the article summarizes the possible benefits of using HPC compared to conventional concrete.


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.


2019 ◽  
Vol 10 (1) ◽  
pp. 12-21
Author(s):  
Abebe Demissew ◽  
Fekadu Fufa ◽  
Sintayehu Assefa

Concrete is a mixture of aggregates and binders. From concrete ingredients, the binder and the costliest and environmental-unfriendly element is cement, which is an ecological unsociable process due to the discharge of CO2 gas into the atmosphere and ecological degradation. Coffee husk (CH) has been considered as a category of agriculture by-product; as its quantity rises, the disposal of it is becoming an environmental problem. Hence, this study investigated the suitability of coffee husk ash (CHA) as a partial replacement for ordinary Portland cement (OPC) in conventional concrete production. Initially, CH samples were collected from different coffee treatment centres. The CHA was then ground and its chemical and physical properties were investigated using Atomic Absorption Spectrophotometer method. After that, the pastes containing OPC and CHA at different levels of replacement were investigated. For this purpose, six different concrete mixes with CHA replacement 0, 2, 3, 5, 10, and 15% of the OPC were prepared for 25MPa conventional concrete with water to cement ratio of 0.5 and 360 kg/m3 cement content. The results of the study show that, up to 10% replacement of OPC by CHA achieved advanced compressive strength at all test ages, i.e. 7, 14, and 28 days of age using compressive test machine.


2020 ◽  
Vol 858 ◽  
pp. 182-187
Author(s):  
Yu Dong Han ◽  
Zhen Bo Wang ◽  
Zi Jie Hong ◽  
Jian Ping Zuo ◽  
Chang Liu ◽  
...  

The brittleness and easiness to crack expose marine concrete to serious durability issues. Engineered Cementitious Composites (ECC), as a new generation of ultra high performance concrete, is expected to overcome the strain-softening properties of traditional concrete and realize function of crack-width control. In this paper, the sulfate erosion of ECC under drying-wetting cycles was modelled in laboratory test. And the compression test on cylinders after exposure to different erosion cycles was implemented to obtain the stress-strain properties. The results disclose that sulfate erosion imposes significant influence on both the nonlinear ascending and descending portions of the stress-strain properties of ECC. As the erosion period extended, ECC strength undergoes an obvious increase. And the descending section of the eroded ECC shows a significant stress drop, which is quite different from that before erosion. Additionally, a simple analytical model was proposed to provide satisfactory prediction of the stress-strain properties of ECC exposed to sulfate erosion.


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