scholarly journals Fly Ash-Based Geopolymer Building Materials for Green and Sustainable Development

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.

2013 ◽  
Vol 438-439 ◽  
pp. 30-35 ◽  
Author(s):  
Nirdosha Gamage ◽  
Sujeeva Setunge ◽  
Kasuni Liyanage

The Victoria State of Australia has the second largest reserves of brown coal on earth, representing approximately 20% of the worlds reserves, and at current use, could supply Victoria with its energy for over 500 years. Its combustion, annually, yields up to 1.3 million tonnes of fly ash, which is largely use for land-fills. Disposal of fly ash in open dumps cause massive environmental problems such as ground water contamination that may create various health problems. This study focuses on the usability of brown coal fly ash to develop a sustainable building material. A series of laboratory investigations was conducted using brown coal fly ash combined with cement and aggregate to prepare cold pressed samples aiming to test their properties. Initial results indicate that compressive strength satisfies minimum standard compressive strength required for bricks or mortar.


2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Ahmad Nurfiki Alwi ◽  
Arif Rahman Setiaji ◽  
Abdurrohim Kurnia Agung ◽  
Abdul Halim

The number of economic needs is one of the fundamental aspects to support the survival of every individual in an area.  If seen in general, the cost of building the building and residential community still use building materials and installation costs are relatively higher.  With the advancement of technology has found a lightweight brick that has better strength, lighter, faster installation and environmentally friendly, so many people began to switch to using lightweight bricks.  For now the price of lightweight brick is still expensive, but this deficiency is covered with the speed of mounting and light weight so overall lightweight brick usage on certain patterns is very profitable.  The use of cement on lightweight bricks leads to high production costs.  With the above problems we have a breakthrough to replace the cement by using zeozolites containing silica compounds that resemble one of the cement compounds.  In this research, cement replacement with Zeolite is 20%, 40% and 60%.  Before use Zeolite was first activated using Fly Ash ratio of 65% Zeolite: 35% Fly Ash and 50% Zeolite: 50% Fly Ash, also activated using Ca (OH) 2 ratio 65% Zeolite: 35% Ca (OH) 2  And 50% Zeolite: 50% Ca (OH) 2.  Thus, there are 15 compositions including the control composition, each composition will be made up of 10 specimens.  Hypothesis testing using two way anova, tested is the effect of cement change treatment with Zeolite and comparison of Zeolite composition with Fly Ash and Ca (OH) 2 to compressive strength, absorption and cost. Keywords: Zeolite, Cement, compressive strength, Cost


2020 ◽  
Vol 165 ◽  
pp. 03029
Author(s):  
Jiangong Yang

Through comparatively analyzing the impermeability and compressive strength test data of nano CaCO3 concrete with different content, this paper puts forward the method of optimizing the durability of nano CaCO3 concrete, and studies the influence of the content of fly ash on the durability of nano CaCO3 concrete on this basis, so as to provide a reference for improving the durability of concrete, so as to improve the recycling and reusing efficiency of building materials, and accelerate the practical application of nano CaCO3 concrete in engineering.


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.


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.


Sign in / Sign up

Export Citation Format

Share Document