scholarly journals The Effect of Nanomaterials on the Properties of Limestone Dust Green Concrete

2021 ◽  
Vol 11 (5) ◽  
pp. 7619-7623
Author(s):  
S. M. Alsaedy ◽  
N. Aljalawi

Portland cement is considered the most involved product in environmental pollution. It is responsible for about 10% of global CO2 emissions [1]. Limestone dust is a by-product of limestone plants and it is produced in thousands of tons annually as waste material. To fulfill sustainability requirements, concrete production is recommended to reduce Portland cement usage with the use of alternative or waste materials. The production of sustainable high strength concrete by using nanomaterials is one of the aims of this study. Limestone dust in 12, 16, and 20% by weight of cement replaced cement in this study. The study was divided into two parts: the first was devoted to the investigation of the best percentage of replacement of waste lime. The second part of the study evaluated the performance of concrete when adding nanomaterials. Three percentages of cement replacement 0.5%, 1%, and 1.5% with nano-Al2O3 were used. The most efficient content of hydrated lime used in this study which achieves sustainability and maintains the quality of concrete was (16%). On the other hand, it was found that the best percentage of nano-Al2O3 as a partial replacement of cement is 1.5%.

2013 ◽  
Vol 634-638 ◽  
pp. 2672-2675
Author(s):  
Zhen Rong Lin ◽  
Tao Zhang ◽  
Yun Yun Xu

As the world's largest building materials production, the mechanical properties of concrete prominent and construction is simple, inexpensive features. Concrete production and construction sectors also exists a very serious problem of environmental pollution, people have to consider how to enhance the environmental protection of concrete, namely, the production and use of "green concrete". Since the past one-sided pursuit of high strength concrete, while ignoring the the durability issues brought a series of questions, allowing people to put forward the concept of a high-performance concrete. The paper by exploring the current development of high-performance green concrete, summary of the proposed method to achieve green high performance concrete.


Author(s):  
Ahmed S. Faried ◽  
Mostafa A. Abo-Hashema ◽  
Abdulrahman E. Roushdy ◽  
Sameh A. Galal

Portland cement (PC) is used in the production of Portland cement concrete (PCC) to construct many infrastructure components such as rigid pavements. This research aims at studying the effect of using common waste materials in Egypt as a replacement of PC in the production of PCC. Using waste materials in concrete production could be an effective measure in maintaining the environment, improving the properties of PCC, and reducing cost of production. Nowadays, pavement technologist and researchers had put their interests on nanotechnology. This paper outlines the innovation of using Nanotechnology-based waste materials as a replacement of PC to enhance the physical and mechanical properties of PCC. The experimental work, using waste materials such as ceramic waste (CW) and ground-granulated blast-furnace slag (GGBFS), was conducted in five phases. In phase 1 and phase 2, different rations were used for CW and GGBFS by weight of cement, respectively. In phase 3, the best three ratios of CW were used with the best ratio of GGBFS. In phase 4, different ratios of CW and GGBFS were used with a standard ratio of Un-Hydrated lime (UHL). In phase-5, various mix of CW, GGBFS and UHL were suggested based on previous results. Modified PCC mixtures were produced, tested and compared to the conventional concrete mixture. Results showed that the cost of PCC production is reduced by 34% in average comparing to the control mix.


2013 ◽  
Vol 357-360 ◽  
pp. 1328-1331
Author(s):  
Bai Rui Zhou ◽  
Dong Dong Han ◽  
Jian Hua Yang ◽  
Yi Liang Peng ◽  
Guo Xin Li

Portland cement, crushed stone, sand and superplasticizer were used to obtain a high strength concrete with a low water to binder ratio. A reticular polypropylene fiber and a single polypropylene fiber were used to improve the strength of the high strength concrete, but the effects of the two fibers on the slump and strengths were quite different. The reasons of the differences were the surface area and the modulus of elasticity of the fibers. The results show the reticular fiber was better to used in high strength concretes.


2016 ◽  
Vol 857 ◽  
pp. 183-188
Author(s):  
C. Mohan Lal ◽  
Vontary Sai Srujan Reddy

High strength concrete has become a design requirement in recent years due to increase in number of infrastructure projects. This paper presents the effect of incorporating Ultra Fine Slag (UFS) and steel fibre to obtain high strength concrete. To achieve target strength of about 80 MPa, it is proposed to the replacement of cement of 10%, 20% and 30% with UFS and incorporating 0.5% and 1.0% fibre in concrete. An experimental investigation is carried out to find the mechanical properties of the concrete. From the test results, it was observed that a compressive strength of 95 MPa was achieved at 30% replacement of cement with UFS and 1.0% fibre content. In addition, there was a significant improvement in split tensile strength and flexural strength of the concrete. This study demonstrates that a high strength concrete can be obtained from partial replacement of cement with UFS and addition of steel fibre.


2020 ◽  
Vol 10 (3) ◽  
pp. 5728-5731 ◽  
Author(s):  
S. A. Chandio ◽  
B. A. Memon ◽  
M. Oad ◽  
F. A. Chandio ◽  
M. U. Memon

This research paper aims at investigating the effects of fly ash as cement replacement in green concrete made with partial replacement of conventional coarse aggregates with coarse aggregates from demolishing waste. Green concrete developed with waste materials is an active area of research as it helps in reducing the waste management issues and protecting the environment. Six concrete mixes were prepared using 1:2:4 ratio and demolishing waste was used in equal proportion with conventional aggregates, whereas fly ash was used from 0%-10% with an increment of 2.5%. The water-cement ratio used was equal to 0.5. Out of these mixes, one mix was prepared with all conventional aggregates and was used as the control, and one mix with 0% fly ash had only conventional and recycled aggregates. The slump test of all mixes was determined. A total of 18 cylinders of standard size were prepared and cured for 28 days. After curing the compressive strength of the specimens was evaluated under gradually increasing load until failure. It is observed that 5% replacement of cement with fly ash and 50% recycled aggregates gives better results. With this level of dosage of two waste materials, the reduction in compressive strength is about 11%.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Iswarya Gowram ◽  
Beulah M ◽  
MR Sudhir ◽  
Mothi Krishna Mohan ◽  
Deekshith Jain

Urbanization and industrialization have dramatically increased the manufacture of cement causing substantial pollution of the environment. The primary global concern related to cement manufacture has been the management of the large carbon footprints. The usages of environmentally friendly cementitious materials in the construction of structures have proved to be a viable option to deal with this environmental concern. Therefore, it is necessary to further explore the usage of cementitious materials which can replace cement albeit partially. In this direction of research, two such cementitious materials, namely, natural zeolite and metakaolin have been investigated in this study. High-strength concrete M60 with natural zeolite and metakaolin as the partial replacements for the cement has been prepared in this work. Polycarboxylic ether-based superplasticizer solution has been used to enhance workability. The test specimen cast and cured for 3, 7, 28, 60, and 90 days at ambient room temperature has been tested for compressive strength, split tensile strength, and flexural strength as per the Indian standards. The optimum mix of high-strength concrete thus manufactured has met the Indian standards, and the combination of cement +5% natural zeolite +10% metakaolin has exhibited the highest compressive, split tensile, and flexural strengths at 90 days of curing. Natural zeolite and metakaolin when used in smaller proportions have increased the concrete strength, and these materials are recommended for partial replacement of cement.


2014 ◽  
Vol 621 ◽  
pp. 30-34
Author(s):  
Eva Vejmelková ◽  
Dana Koňáková ◽  
Monika Čáchová ◽  
Martin Keppert ◽  
Adam Hubáček ◽  
...  

Natural zeolite rocks are known to be able to act as Supplementary Cementitious Materials (SCM) in Portland cement based concrete. Generally SCMs are reacting with portlandite and providing binding hydration products just as Portland cement does. In this way an SCM can substitute certain amount of Portland cement in concrete and thus reduce the related energy consumption and CO2 generation. Due to a large variability of SCMs composition and properties there is not any general rule for an optimum Portland cement substitution level. In this paper, the influence of natural zeolite rock on selected mechanical, hygric and thermal properties of concrete is studied. Experimental results show that the analyzed zeolite is acting as a pozzolan but for higher amounts its application leads to an increase in concrete porosity which affects its properties in a significant way.


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