scholarly journals Effect of different curing conditions on flexural and compressive strength of fly ash mortars

2016 ◽  
Vol 22 (6) ◽  
pp. 396-399
Author(s):  
Şemsi Yazıcı ◽  
Gözde İnan Sezer
2012 ◽  
Vol 626 ◽  
pp. 937-941 ◽  
Author(s):  
W.I. Wan Mastura ◽  
H. Kamarudin ◽  
I. Khairul Nizar ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
H. Mohammed

This paper reports the results of an experimental work conducted to investigate the effect of curing conditions on the properties of fly ash-based geopolymer bricks prepared by using fly ash as base material and combination of sodium hydroxide and sodium silicate as alkaline activator. The experiments were conducted by varying the curing time in the range of 1-24 hours respectively. The specimens cured for a period of 24 hours have presented the highest compressive strength for all ratio of fly ash to sand. For increasing curing time improve compressive strength and decreasing water absorption.


Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5699
Author(s):  
Rosicky Methode Kalombe ◽  
Victor Tunde Ojumu ◽  
Chuks Paul Eze ◽  
Sammy Mwasaha Nyale ◽  
John Kevern ◽  
...  

This study reports on formulations and conditions for producing fly ash-based geopolymers with a view to showing that the compressive strength required for construction applications can be obtained without the addition of aggregates, sand, and/or cement. It was shown in a series of experiments constituting at least 73% fly ash that a compressive strength of up to 90 MPa can be obtained depending on the curing conditions. While high alkalinity resulted in stronger materials, the results showed about 40% savings in CO2 emissions without using sand and cement. Such materials are suited for construction applications with minimal environmental impact.


2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Pu Zhang ◽  
Yiliang Huang ◽  
Yongqi Li ◽  
Jun Zhao ◽  
Hengqian Dong ◽  
...  

Ultrahigh-performance fiber-reinforced concrete (UHPFRC) is a new type of concrete with excellent performance and good application prospects. However, expensive heat curing or high-pressure curing was often adopted to ensure the sufficient compressive strength. This study focuses on improving the compressive strength and workability of UHPFRC by changing the composition materials and the mixture ratios under standard curing conditions. The 0-1 mm and 1∼3 mm sintered bauxite was adopted as coarse aggregate. UHPFRC with high compressive strength and good workability was developed by changing the water-binder ratios, by adding ground-granulated blast furnace slag (GGBFS) or fly ash, and by changing the bauxite content of different particle sizes. When the volume ratio of steel fiber was 3%, the recommend water to binder ratio was 0.194 according to this experiment, the dosage of GGBFS-replaced cement is recommended as 20%, the dosage of fly ash instead of silica fume is recommended as 30%. The recommend ratio of 0-1 mm and 1∼3 mm sintered bauxite was 1.51 : 1. Finally, a kind of UHPFRC material with a compressive strength of 152.4 MPa and a slump of 120 mm was developed under the standard curing conditions.


2011 ◽  
Vol 250-253 ◽  
pp. 178-181
Author(s):  
Ya Ding Zhao ◽  
Xue Ying Li ◽  
Ling Chao Kong ◽  
Wei Du

Under variable temperature curing conditions(30 oC ~70 oC), concrete with fly ash whose compressive strength, flexural strength, and dynamic elastic modulus are better than ones without fly ash.Compared with constant temperature 20oC, 50 oC and 70 oC, variable temperature curing(VTC) is benefit for the improvement of mechanical properties of 30% fly ash concrete, but which is no advantage to improve performance of 50% fly ash concrete.


2010 ◽  
Vol 168-170 ◽  
pp. 532-536 ◽  
Author(s):  
Guo Li ◽  
En Li Lu ◽  
Peng Wang ◽  
Ou Geng ◽  
Yong Sheng Ji

In order to study the influences of initial curing conditions on fly ash (FA) cement concrete durability, fly ash cement samples with 30% replacement ratio were fabricated and cured in water at 10°C, 20°C, 30°Cand 40°C for 3d, 7d, 14d and 28d respectively. Hydration degrees of fly ash at early age were measured using the selective dissolve method. Correspondingly the pore structure and morphology of FA-cement mortar and compared cement mortar were studied by using MIP and SEM methods. Then early age compressive strengths of FA-cement concrete and compared normal cement concrete were tested. Experimental results show that initial curing temperatures and ages are important factors to fly ash early age hydration degree, FA-cement system microstructure, morphology and early age compressive strength etc. High curing temperatures and longer curing time can lead higher fly ash hydration degree, and then higher compressive strength of FA-cement concrete, and make the micro-structures of fly ash-cement system denser.


Author(s):  
Anıl Niş ◽  
İlhan Altındal

This study investigated the influence of different curing conditions on the compressive strength (CS) of the different alkali activated concrete (AAC) specimens at the ages of 2, 28, and 90 days for the structural utilization and standardization process of AAC instead of OPC concrete. For this aim, 100% slag (S100), 75% slag and 25% fly ash (S75FA25), and 50% slag and 50% fly ash based (S50FA50) AAC specimens were produced. Based on the oven-curing (O), water-curing (W), and ambient-curing (A) methods, the influence of 2O for 2 days, 26A2O, 2O26A, 28A, 28W, 26W2O, and 2O26W for 28 days, and 88A2O, 2O88A, 90A, 88W2O, 2O88W, 90W for 90 days on the CS of the AAC were examined in details. In addition, the influence of delayed oven-curing conditions on CS development was also investigated. The results indicated that curing conditions significantly affected on the CS and the water-curing condition could provide a better CS for those of AAC at 90 days. Although, the oven-curing enhanced CS of the S100 specimens at initial ages (first oven-curing applied), delayed oven-curing (oven-curing applied later) was found significant for S75FA25 and S50FA50 specimens. The delayed oven-curing affected more on the CS of the AAC when fly ash content increased. The most of AAC specimens with oven-curing had significantly enhanced the CS at 28 days, but S50FA50 at the age of 90 days decreased. Different curing regimes were proposed for the superior compressive strength values for each AAC specimens at the ages of 28 and 90 days.


2011 ◽  
Vol 374-377 ◽  
pp. 1523-1526 ◽  
Author(s):  
Fan Wang ◽  
Yi He Zhang ◽  
Tong Zhao ◽  
An Zhen Zhang

A series of foam concrete with different content of fly ash or red mud were experimentally investigated in this study. The results indicated that the water-solids ratio of optimized material proportion and curing conditions were 0.5, and the compressive strength and density of the concrete compressive would fall with the addition of fly ash or red mud.


2013 ◽  
Vol 686 ◽  
pp. 227-233 ◽  
Author(s):  
Mustafa Al Bakri Abdullah Mohd ◽  
Liyana Jamaludin ◽  
Kamarudin Hussin ◽  
Mohammed Binhussain ◽  
Che Mohd Ruzaidi Ghazali ◽  
...  

Geopolymer is cementitious binders that do not require the presence of ordinary Portland cement (OPC). Fly ash with geopolymer formulations prepared with mixing alumino-silicate with the alkaline activator solution has been applied as protective coating material that suitable for high temperature applications such as fire resistant panel. Geopolymer coating samples were cured at 70 °C for 24 hours before sintered using temperatures range from 600 °C to 1500 °C in order to increase strength and improve thermal properties. Curing conditions also have a significant effect on the development of mechanical strength in most cementitious systems. The chemical compositions, microstructure and FTIR were studied. Geopolymer coating samples cures to a glassy texture and effectively used to create a resistant surface. Fly ash geopolymer coating was improved the compressive strength of the coatings materials as high as 40 MPa. This technology develop a geopolymeric mix design that superior use as cementitious coatings with high thermal application.


2011 ◽  
Vol 99-100 ◽  
pp. 960-964 ◽  
Author(s):  
Xue Ying Li ◽  
En Zu Zheng ◽  
Chun Long Ma

The compressive strength of geopolymer prepared from a class C fly ash (CFA) at different curing conditions and mass ratio of water to fly ash were investigated. The geopolymer was activated with a mixed solution of sodium hydroxide (NaOH) and sodium silicate. The results revealed that the obtained compressive strength was in the range of 11.7~61.9MPa and the compressive strength decreased with the increment of the mass ratio of water to CFA (W/F). The geopolymer samples with the highest strength were obtained when W/F was 0.30 with proper delay time 1d before being demoulded and then followed by curing at 60°C for 24h. For geopolymer with lower W/F (0.30), its optimum curing temperature was better not higher than 60°C, however, for the higher W/F, the curing temperature was suit to more than 70°C.


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