Effect of Treated Sago Pith Waste Ash and Silica Fume to the Mechanical Properties of Fly Ash-Based Geopolymer Brick

2021 ◽  
Vol 879 ◽  
pp. 100-114
Author(s):  
Izwan B. Johari ◽  
Md Azlin Md Said ◽  
Mohd Amirul B. Mohd Snin ◽  
Nur Farah Aqilah Bt. Ayob ◽  
Nur Syafiqah Bt. Jamaluddin ◽  
...  

This paper investigates the effect of partial replacement of fly ash with sago pith waste ash and silica fume in fabricating the geopolymer mortar concrete. The mixtures of geopolymer mortar concrete were prepared by replacing sago pith waste ash and silica fume at 5% of total weight of fly ash. There were six specimens of geopolymer mortar cubes and bricks fabricated in this study. The specimens are tested with compressive strength test, rebound hammer test and ultrasonic pulse velocity test. The results from the tests are compared with some existing published works as to clarify the effect of replacing the fly ash with sago waste and silica fume on the strength of concrete. Comparisons had been made and concluded that the molarity of alkaline solution, Al3O2 and CaO influenced the development of compressive strength along the curing time of fly ash based geopolymer concrete.

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
B. Ravali ◽  
K. Bala Gopi Krishna ◽  
D. Ravi Kanth ◽  
K. J. Brahma Chari ◽  
S. Venkatesa Prabhu ◽  
...  

Need of construction is increasing due to increase in population growth rate. The geopolymer concrete is eco-friendly than ordinary concrete. Current experimental investigation was conducted on ordinary and geopolymer concrete using nondestructive testing (NDT) tests like ultrasonic pulse velocity (UPV) test and rebound hammer (RH) test. Cube specimens of dimensions 150 mm × 150 mm × 150 mm are used to conduct these tests at 7, 14, and 28 days. Proportions considered for concrete are cement-fly ash-river sand (100-0-100% and 60-40-100%), cement-fly ash-robo sand (100-0-100% and 60-40-100%) whereas geopolymer concrete fly ash-metakaolin is taken in proportions of 100-0%, 60-40%, and 50-50%. Alkaline activators (sodium hydroxide and sodium silicate with molarity 12M) were used in preparing geopolymer concrete. The major objective of the current study is to obtain relation between compressive strength of concrete and UPV values.


2016 ◽  
Vol 11 (2) ◽  
pp. 53-66 ◽  
Author(s):  
Sudarshan Dattatraya Kore ◽  
A. K. Vyas

Abstract A huge amount waste (approximately 60%) is generated during mining and processing in marble industries. Such waste can be best utilized in infrastructure development works. Coarse aggregate 75% by weight was replaced by aggregate obtained from marble mining waste. The impact of marble waste as a partial replacement for conventional coarse aggregate on the properties of concrete mixes such as workability, compressive strength, permeability, abrasion, etc. was evaluated. The test results revealed that the compressive strength was comparable to that of control concrete. Other properties such as workability of concrete increased, water absorption reduced by 17%, and resistance to abrasion was marginally increased by 2% as compared to that of control concrete. Ultrasonic pulse velocity and FTIR results show improvement in quality of concrete with crushed marble waste. From the TGA analysis it was confirmed that, aggregate produced from marble waste shows better performance under elevated temperature than that of conventional aggregates.


Author(s):  
F. C. Parida ◽  
S. K. Das ◽  
A. K. Sharma ◽  
P. M. Rao ◽  
S. S. Ramesh ◽  
...  

Hot sodium coming in contact with structural concrete in case of sodium leak in FBR system cause damage as a result of thermo-chemical attack by burning sodium. In addition, release of free and bound water from concrete leads to generation of hydrogen gas, which is explosive in nature. Hence limestone concrete, as sacrificial layer on the structural concrete in FBR, needs to be qualified. Four concrete blocks of dimension 600mm × 600mm × 300mm with 300mm × 300mm × 150mm cavity were cast and subjected to controlled sodium exposure tests. They have composition of ordinary portland cement, water, fine and coarse aggregate of limestone in the ratio of 1 : 0.58 : 2.547 : 3.817. These blocks were subjected to preliminary inspection by ultrasonic pulse velocity technique and rebound hammer tests. Each block was exposed for 30 minutes to about 12 kg of liquid sodium (∼ 120 mm liquid column) at 550° C in open air, after which sodium was sucked back from the cavity of the concrete block into a sodium tank. On-line temperature monitoring was carried out at strategic locations of sodium pool and concrete block. After removing sodium from the cavity and cleaning the surfaces, rebound hammer testing was carried out on each concrete block at the same locations where data were taken earlier at pre-exposed stage. The statistical analysis of rebound hammer data revealed that one of the concrete block alone has undergone damage to the extent of 16%. The loss of mass occurred for all the four blocks varied from 0.6 to 2.4% due to release of water during the test duration. Chemical analysis of sodium in concrete samples collected from cavity floor of each block helped in generation of depth profiles of sodium monoxide concentration for each block. From this it is concluded that a bulk penetration of sodium up to 30 mm depth has taken place. However it was also observed that at few local spots, sodium penetrated into concrete up to 50 mm. Cylindrical core samples of 50 mm × 150 mm long were obtained from the exposed cavity and tested for compressive strength and longitudinal ultrasonic pulse velocity (UPV). These are compared with core samples obtained from concrete cubes used as standard reference. The average reduction in UPV and compressive strength were 7% and 29% respectively indicating marginal degradation in mechanical properties of sodium-exposed concrete.


Author(s):  
Thushara Raju ◽  
Namitha S ◽  
Muhammed Nabil K ◽  
Mohammed Rafeeque N. V ◽  
Reshma Sundhar ◽  
...  

Alkali Activated Material (AAM) is introduced as a pioneering construction material in the construction diligence to trim down the utilization of Ordinary Portland Cement (OPC) and to curtail the amount of carbon dioxide released during the production of OPC. Modestly refined industrial by products or natural materials rich in alumino silicates are the binding agents used in AAM. Generally, heat curing is needed for the alkali activated mortar to achieve the required hardened properties and this difficulty can be overcome by adding slag to the mix. In this experimental analysis, the alkali activated mortar mixes with different proportions of glassy granulated slag and Class F fly ash were prepared without the usage of superplasticizers, with alkali to binder (a/b) ratios of 0.7, 0.8 and 0.9. The rheological characteristics of mortar were studied using flow table apparatus and hardened properties were studied using compressive strength test and ultrasonic pulse velocity (UPV) test by testing cylindrical specimens of size 25 mm diameter and 50 mm height. The mortar specimens were air-cured, and the compressive strength and UPV test were conducted after 3 and 7 days. The test results showed that due to the presence of higher alkali content and the decrease in slag content, the workability of alkali activated mortar was improved, but the measure of strength decreased. The mix with 100% slag and a/b ratio of 0.8 had the best UPV value, indicating its quality among the various mortar mixes studied. This study portrays the significance of optimising the alkali and slag content in tailor making an alkali activated mortar system with good hardened properties.


NanoNEXT ◽  
2021 ◽  
pp. 1-15
Author(s):  
Darweesh H.H.M

Physical, chemical and mechanical properties of high belite cement (HBC) blended with high pulverized fly ash (HPFA) with stable ratio of silica fume (SF) in comparison with Portland cement (OPC) were investigated. Results showed that the water of consistency and setting times (Initial and final) tended to increase with the increase of HPFA content. The bulk density and compressive strength were also improved and enhanced with the increase of HPFS content at all hydration times, but only up to 15 % HPFA, and then decreased with further increase.  However, the total porosity slightly decreased, but started to increase with further increase of >15 % HPFA. The free lime content of the pure OPC and HBC gradually were increased as the hydration times progressed up to 90 days, while those of blended cements increased only up to 7 days and then decreased onward. The results were confirmed by measuring the heat of hydration and ultrasonic pulse velocity for the optimum cement pastes comparing with those of both OPC and HBC. The heat of hydration of the optimum cement pastes was decreased at all hydration times and become lower than those of OPC and HBC. The ultrasonic pulse velocity test (USPV) proved that the uniformity and quality of the matrix of the hardened cement pastes are good with no cracks.


2021 ◽  
Vol 895 ◽  
pp. 59-67
Author(s):  
Mayadah W. Falah ◽  
Alaa Adnan Hafedh ◽  
Safa A. Hussein ◽  
Zainab S. Al-Khafaji ◽  
Ali A. Shubbar ◽  
...  

To manufacture high-strength and high-performance concrete, the incorporation of silica fume with concrete was becoming popular nowadays. When utilizing various amounts of cement substitute products, the design becomes even more complicated. The latest research has been dedicated to researching the applicability of cement substitute products for cement kiln dust (CKD) and silica fume (SF). In permeability and compressive strength terms, the effect of these components on the efficacy of the concrete would be studied. Also, the materials proposed might limit greenhouse gas emissions, which will mitigate climate change on other causes of global pollution. Casting a standard concrete cube (100 percent OPC) equivalent to (150 gm) would initiate the experiment, which was utilized later for comparative purposes. The industrial waste materials (SF and CKD) was be applied as cement substitution proportions (10 percent, 20 percent, and 30 percent) of the dry cement weight at varying percentages of each component (5 percent, 10 percent, and 15 percent). Eventually, after 7, 14, 28 days, the compressive strength shift would be calculated. The permeability of the latest concrete will be checked after (7, 14, and 28) days of healing utilizing ultrasonic pulse velocity (UPV) technology. The experimental findings indicate that with a specimen comprising 20 percent of (SF and CKD) relative to (100 percent OPC) specimen, there is an improvement in compressive intensity and pulse velocity values in various curing times and specimens of various (SF and CKD) specimen M3 have a decrease in pulse velocity value after 7 curing days.


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