scholarly journals Influence of Curing Time on the Drying Shrinkage of Concretes with Different Binders and Water-to-Binder Ratios

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Jun Yang ◽  
Qiang Wang ◽  
Yuqi Zhou

Plain cement concrete, ground granulated blast furnace slag (GGBS) concrete, and fly ash concrete were designed. Three wet curing periods were employed, which were 2, 5, and 8 days. The drying shrinkage values of the concretes were measured within 1 year after wet curing. The results show that the increasing rate of the drying shrinkage of concrete containing a mineral admixture at late age is higher than that of plain cement concrete regardless of the wet curing time. With the reduction of wet curing time, the increment of total drying shrinkage of concrete decreases with the decrease of the W/B ratio. The negative effects on the drying shrinkage of fly ash concrete due to the reduction of the wet curing time are much more obvious than those of GGBS concrete and plain cement concrete. Superfine ground granulated blast furnace slag (SGGBS) can reduce the drying shrinkage of GGBS concrete and fly ash concrete when the wet curing time is insufficient.

2011 ◽  
Vol 99-100 ◽  
pp. 420-425 ◽  
Author(s):  
Qian Rong Yang ◽  
Xiao Qian Wang ◽  
Hui Ji

The strength, expansion and amount of scaling of concrete with compound mineral admixture (CMA) from steel slag, granulated blast furnace slag and fly ash were studied. The result shows that damage by crystallization press from sulfate attack when concrete was exposed to sulfate environments under wetting–drying alternation is much larger than that from sulfate chemical attack. Adding CMA to concrete could reduce the damage from expansion of concrete caused by sulfate chemical attack, but the resistance of concrete to damage by crystallization press from sulfate attack was remarkably reduced.


2021 ◽  
Vol 13 (2) ◽  
pp. 873
Author(s):  
Numanuddin M. Azad ◽  
S.M. Samindi M.K. Samarakoon

There has been a significant movement in the past decades to develop alternative sustainable building material such as geopolymer cement/concrete to control CO2 emission. Industrial waste contains pozzolanic minerals that fulfil requirements to develop the sustainable material such as alumino-silicate based geopolymer. For example, industrial waste such as red mud, fly ash, GBFS/GGBS (granulated blast furnace slag/ground granulated blast furnace slag), rice husk ash (RHA), and bagasse ash consist of minerals that contribute to the manufacturing of geopolymer cement/concrete. A literature review was carried out to study the different industrial waste/by-products and their chemical composition, which is vital for producing geopolymer cement, and to discuss the mechanical properties of geopolymer cement/concrete manufactured using different industrial waste/by-products. The durability, financial benefits and sustainability aspects of geopolymer cement/concrete have been highlighted. As per the experimental results from the literature, the cited industrial waste has been successfully utilized for the synthesis of dry or wet geopolymers. The review revealed that that the use of fly ash, GBFS/GGBS and RHA in geopolymer concrete resulted high compressive strength (i.e., 50 MPa–70 MPa). For high strength (>70 MPa) achievement, most of the slag and ash-based geopolymer cement/concrete in synergy with nano processed waste have shown good mechanical properties and environmental resistant. The alkali-activated geopolymer slag, red mud and fly ash based geopolymer binders give a better durability performance compared with other industrial waste. Based on the sustainability indicators, most of the geopolymers developed using the industrial waste have a positive impact on the environment, society and economy.


2018 ◽  
Vol 7 (1) ◽  
pp. 19-23
Author(s):  
S. Thirupathiraj .

Cement is the core content for the concrete mix. Manufacturing of cement causes CO2 emission which leads to the pollution, health and environmental problems like global warming to control over the adverse effect we can prefer geopolymer concrete which is not a cement concrete. Factory wastes such as fly ash, ground granulated blast furnace slag (GGBS), silica fume and Metakaolin can be used as alternate for cement. This study mainly focus on the ratio of fly ash and ground granulated blast furnace slag (GGBS) for optimum levels which nearly matches the cement concrete properties. This study involves the various tests like slump flow, compression testing, split tensile strength and flexural strength of self-compacting geopolymer concrete. Self-compacting concrete is a highly flowable concrete that spreads into the form without the need of mechanical vibration. Self-compacting concrete is a non-segregating concrete that is placed by means of its own weight. The advantages include improved constructability, Labour reduction, bond to steel, Flow into complex forms, reduced equipment wear etc. The aim of this study is to achieve an optimum self-compacting concrete geopolymer concrete mix proportion using fly ash and ground granulated blast furnace slag (GGBS). Then the study will be further extended by investigating the durability properties of self-compacting geopolymer concrete.


2011 ◽  
Vol 477 ◽  
pp. 366-374
Author(s):  
Jian Hua Wu ◽  
Yun Lan Liu

This paper studies the influence of different mineral admixtures(fly ash and ground granulated blast furnace slag)on the carbonation resistance and chloride permeability of steam-cured HPC. The test results show that under the condition of steam-cured and standard-cured, incorporating 20-30% of the ground granulated blast furnace slag or 15-20% of fly ash decreased the alkalinity and the carbonation resistance of the concrete; with the increase of the proportion of the mineral admixture in concrete, carbonation resistance of HPC was decreased; incorporating 20-30% of the ground granulated blast furnace slag or 15-20% of fly ash improved the chloride permeability of steam-cured concrete, and the influence of ground granulated blast furnace slag is better than that of the fly ash.


Structures built with normal concrete are fading out from the construction industry due to the development of high strength concrete. The massive structures such as sky scrapers, bridges, tunnels, nuclear plants, underground structures need high strength concrete to withstand the high intensity vertical, horizontal and moving loads etc. The development of high strength alkaline activated concrete will reduce the usage of cement in construction community. Lesser the utilisation of cement will lessen the high emission of carbon dioxide gas into the atmosphere. In this study, high strength concrete using alumina and silica rich materials are made with a mix ratio of 1:1.31:2.22. The water to cement ratio for high strength cement concrete and the alkaline solution to binder ratio for alkaline activated concrete are kept as 0.35. Low calcium fly ash, Ground Granulated Blast Furnace Slag (GGBS) and Metakaolin are used as binders and Manufacturing Sand is used as fine aggregate to made high strength alkaline activated concrete. The high strength alkaline activated concrete tests results are better than the high strength cement concrete.


Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 596
Author(s):  
Yasuhiro Dosho

To improve the application of low-quality aggregates in structural concrete, this study investigated the effect of multi-purpose mineral admixtures, such as fly ash and ground granulated blast-furnace slag, on the performance of concrete. Accordingly, the primary performance of low-quality recycled aggregate concrete could be improved by varying the replacement ratio of the recycled aggregate and using appropriate mineral admixtures such as fly ash and ground granulated blast-furnace slag. The results show the potential for the use of low-quality aggregate in structural concrete.


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