scholarly journals Production of Ultra-High-Performance Concrete with Low Energy Consumption and Carbon Footprint Using Supplementary Cementitious Materials Instead of Silica Fume: A Review

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8291
Author(s):  
Mays A. Hamad ◽  
Mohammed Nasr ◽  
Ali Shubbar ◽  
Zainab Al-Khafaji ◽  
Zainab Al Masoodi ◽  
...  

The increase in cement production as a result of growing demand in the construction sector means an increase in energy consumption and CO2 emissions. These emissions are estimated at 7% of the global production of CO2. Ultra-high-performance concrete (UHPC) has excellent mechanical and durability characteristics. Nevertheless, it is costly and affects the environment due to its high amount of cement, which may reach 800–1000 kg/m3. In order to reduce the cement content, silica fume (SF) was utilized as a partial alternative to cement in the production of UHPC. Nevertheless, SF is very expensive. Therefore, the researchers investigated the use of supplementary cementitious materials cheaper than SF. Very limited review investigates addressed the impact of such materials on different properties of UHPC in comparison to that of SF. Thus, this study aims to summarize the effectiveness of using some common supplementary cementitious materials, including fly ashes (FA), ground granulated blast furnace slag (GGBS), metakaolin (MK) and rice husk ashes (RHA) in the manufacturing of UHPC, and comparing the performance of each material with that of SF. The comparison among these substances was also discussed. It has been found that RHA is considered a successful alternative to SF to produce UHPC with similar or even higher properties than SF. Moreover, FA, GGBS and MK can be utilized in combination with SF (as a partial substitute of SF) as a result of having less pozzolanic activity than SF.

DYNA ◽  
2019 ◽  
Vol 86 (211) ◽  
pp. 84-93 ◽  
Author(s):  
Nancy Torres Castellanos ◽  
Jaime Antonio Fernández Gómez ◽  
Andres Mauricio Nuñez Lopez

Ultra-high-performance concrete (UHPC) is the essential innovation in concrete research of the recent decades. However, because of the high contents of cement and silica fume used, the cost and environmental impact of UHPC is considerably higher than conventional concrete. The use of industrial byproducts as supplementary cementitious materials, in the case of recycled glass powder and fluid catalytic cracking catalyst residue (FCC), the partial substitution of cement and silica fume allows to create a more ecological and cost-efficient UHPC. This research presents a study to determine the possibility of partial substitution of cement by FCC in a previously optimized mixture of ultra-high-performance concrete with recycled glass. The results demonstrate that compressive strength values of 150 and 151 MPa without any heat treatment can be achieved, respectively, when replacing 11% and 15% of the cement with FCC, for a determined amount of water and superplasticizer, compared to 158 MPa obtained for the reference UHPC without any FCC content. The rheology of fresh UHPC is highly decreased by replacing cement particles with FCC.


Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1929 ◽  
Author(s):  
Yu-You Wu ◽  
Jing Zhang ◽  
Changjiang Liu ◽  
Zhoulian Zheng ◽  
Paul Lambert

Nanomaterials have been increasingly employed for improving the mechanical properties and durability of ultra-high-performance concrete (UHPC) with high volume supplementary cementitious materials (SCMs). Recently, graphene oxide (GO) nanosheets have appeared as one of the most promising nanomaterials for enhancing the properties of cementitious composites. To date, a majority of studies have concentrated on cement pastes and mortars with fewer investigations on normal concrete, ultra-high strength concrete, and ultra-high-performance cement-based composites with a high volume of cement content. The studies of UHPC with high volume SCMs have not yet been widely investigated. This paper presents an experimental investigation into the mini slump flow and physical properties of such a UHPC containing GO nanosheets at additions from 0.00 to 0.05% by weight of cement and a water–cement ratio of 0.16. The study demonstrates that the mini slump flow gradually decreases with increasing GO nanosheet content. The results also confirm that the optimal content of GO nanosheets under standard curing and under steam curing is 0.02% and 0.04%, respectively, and the corresponding compressive and flexural strengths are significantly improved, establishing a fundamental step toward developing a cost-effective and environmentally friendly UHPC for more sustainable infrastructure.


2019 ◽  
Vol 13 (1) ◽  
pp. 147-162 ◽  
Author(s):  
Edwin Paul Sidodikromo ◽  
Zhijun Chen ◽  
Muhammad Habib

Introduction: Ultra-High-Performance Concrete (UHPC) is an advanced type of concrete in the Civil Engineering industry. It is a cement-based composite which exhibits improved mechanical and durable properties showing a high compressive strength of not less than 150 MPa and high tensile strength of not less than 7 MPa. Objective: In this article, a review of the use of a different type of supplementary cementitious materials (SCMs) including fibers is made for obtaining the desired UHPC. Discussion and Conclusion: For this, it is vital to understand the principles of UHPC. UHPC has several advantages over normal strength concrete (NSC) and high strength concrete (HSC) with some commercially ready UHPC’s available, but the use of it is restricted due to the limited design codes. The influence of the curing type also plays a vital role in the overall performance of UHPC.


2021 ◽  
Vol 72 (1) ◽  
pp. 76-83
Author(s):  
Lam Le Hong ◽  
Lam Dao Duy ◽  
Huu Pham Duy

The demand for High Performance Concrete (HPC) is steadily increasing with massive developments. Conventionally, it is possible to use industrial products such as silica fume (SF), fly ash, as supplementary cementitious materials (SCM), to enhance the attributes of HPC. In recent years, nano-silica (NS) is used as an additive in added mainly to fill up the deviation arises with the addition of SF for HPC. This study aims to optimize the proportion of NS (produced in Vietnam) in the mixture used for fabricating 70 MPa high-performance concrete. SiO2 powder with particle size from 10 to 15 nm were used for mixing. A series of compressive strength test of HPC with nano-SiO2 varied from 0 to 2.8 percent of total of all binders (0%, 1.2%, 2%, 2.8%), and the fixed percentage of silica fume at 8% were proposed. Results show compressive strength increases with the increase of nano-SiO2, but this increase stops after reaching 2%. And at day 28 of the curing period, only concrete mixture containing of 8% silica fume and 2% nano-SiO2, had the highest compressive strength.


2019 ◽  
Vol 271 ◽  
pp. 07006
Author(s):  
Elsy Y. Flores ◽  
Jordan Varbel ◽  
Craig M. Newtson ◽  
Brad D. Weldon

Many existing bridges have adjacent girders that utilize grouted shear keys to transfer loads laterally across the superstructure. Cracking and leaking often cause degradation of the shear key and the girder. This work investigates the potential for using non-proprietary ultra-high performance concrete (UHPC) as a grouting material for repair of deteriorated shear keys by testing bond strength between UHPC and substrate concrete surfaces that were either formed or scarified by chipping. Bond strengths were adequate for both surface textures even though texture depth was substantially less than recommended by ACI 546. Scanning electron microscopy has also been used to investigate the bonded area. This microscopic scanning has shown fly ash residue remaining on the substrate after bond failure, indicating that the supplementary cementitious materials produce much of the bond. Ongoing work for this project also includes full-scale testing of UHPC shear keys between pre-stressed channel girders.


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