scholarly journals Performance of Self-compacting Concrete with Stainless Steel Slag Versus Fly Ash as Fillers: A Comparative Study

2021 ◽  
Author(s):  
Yeong-Nain Sheen ◽  
Duc-Hien Le ◽  
My Ngoc-Tra Lam
Keyword(s):  
Stainless Steel ◽  
Compressive Strength ◽  
Fly Ash ◽  
Setting Time ◽  
Steel Slag ◽  
Strength Loss ◽  
Comparative Investigation ◽  
Self Compacting Concrete ◽  
Stainless Steel Slag ◽  
Initial Setting Time

Recently, stainless steel slag -a byproduct of manufacturing stainless steel is accepted as a cementitious material, the chemical characteristics of which are highly variant. This study reuses two types of stainless steel reducing slag with specific surface area of 1766 cm2/g (S1) and 7970 cm2/g (S2) in developing self-compacting concrete (SCC). Particularly, two S2-blended SCCs incorporating with S1 and fly ash as fillers (calling as S-mix and F-mix) were prepared for a comparative investigation. In both SCCs, ordinary Portland cement was replaced by S2 with various ratios (from 0 % to 50 %, increment 10 %). Testing results show that in fresh state, the F-mix exhibits higher workability and longer initial setting time than those of S-mix. In hardened state, 10 % compressive strength loss was realized as increasing S2 content up to 30 % in the both SCCs; the strength of F-mix is up to 1.9 times of S-mix at the same rate of S2 replacement. Water absorption of the F-mix was below 3 %, suggested as a “good” quality concrete; whilst the S-mix could be longs to an “average” one. Resistivity and sulfate resistance of F-mix are considerably higher than those of S-mix. Moreover, based on the obtained data, compressive strength and electrical resistivity are correlated well with a logarithmic form.

scholarly journals Alkali-Activated Stainless Steel Slag as a Cementitious Material in the Manufacture of Self-Compacting Concrete

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3945
Author(s):  
Julia Rosales ◽  
Francisco Agrela ◽  
José Luis Díaz-López ◽  
Manuel Cabrera
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Fly Ash ◽  
Steel Slag ◽  
Cementitious Material ◽  
Self Compacting Concrete ◽  
Stainless Steel Slag ◽  
Alkali Activated ◽  
Activating Solution

This work develops the manufacture of self-compacting concrete (SCC) with 50% cement reduction. As an alternative binder to cement, the viability of using an alkali-activated combination of stainless steel slag (SSS) and fly ash (FA) has been demonstrated. SSS was processed applying three different treatments. Binders were manufactured mixing 35% SSS with 65% FA, as precursors, and a hydroxide activating solution. This binder was replaced by the 50% cement for the manufacture of SCC. The results obtained show good mechanical properties and durability. The study shows a reduction in the use of cement in the manufacture of SCC reusing two wastes.

Effect of high temperature on SCC containing fly ash

2021 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Mehmet Canbaz ◽  
Erman Acay
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Fly Ash ◽  
Concrete Strength ◽  
Experimental Studies ◽  
Strength Loss ◽  
Ultrasonic Pulse Velocity ◽  
Pulse Velocity ◽  
Unit Weight ◽  
Self Compacting Concrete

The effect of high temperature on self-compacting concrete, which contains different amounts of fly ash, has been investigated. By considering the effect of concrete age and increased temperatures, the optimum fly ash-cement ratio for the optimum concrete strength is determined using experimental studies. Self-compacting concrete specimens are produced, with fly ash/cement ratios of 0%, 20% and 40%. Specimens were cured for 28, 56 and 90 days. After curing was completed, the specimens were subjected to temperatures of 20°C, 100°C, 400°C, 700°C and 900°C for three hours. After the cooling process, tests were performed to determine the unit weight, ultrasonic pulse velocity and compressive strength of the specimens. According to the experiment results, an increase in fly ash ratio causes a decrease in the compressive strength of self-compacting concrete. However, it positively contributes to self-compaction and strength loss at high temperatures. The utilization of fly ash in concrete significantly contributes to the environment and the economy. For this reason, the addition of 20% fly ash to concrete is considered to be effective.

scholarly journals Investigation on the Compressive Strength and Time of Setting of Low-Calcium Fly Ash Geopolymer Paste Using Response Surface Methodology

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3461
Author(s):  
Pauline Rose J. Quiatchon ◽  
Ithan Jessemar Rebato Dollente ◽  
Anabel Balderama Abulencia ◽  
Roneh Glenn De Guzman Libre ◽  
Ma. Beatrice Diño Villoria ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Unconfined Compressive Strength ◽  
Setting Time ◽  
Initial Setting Time ◽  
Alkali Activator ◽  
Setting Times ◽  
Confirmatory Tests ◽  
Initial Setting

Approximately 2.78 Mt of coal fly ash is produced in the Philippines, with a low utilization rate. Using fly ash-based geopolymer for construction will lessen the load sent to landfills and will result in lower GHG emissions compared to OPC. It is necessary to characterize the fly ash and optimize the geopolymer components to determine if it can replace OPC for in situ applications. The activator-to-precursor ratio, the water-to-solids ratio, and the sodium hydroxide-to-sodium silicate ratio were optimized using a randomized I-optimal design from the experimental results of 21 runs with five replicates, for a total of 105 specimens of 50 mm × 50 mm × 50 mm paste cubes. The engineering properties chosen as the optimization responses were the unconfined compressive strength (UCS), the initial setting time, and the final setting time. The samples were also ambient-cured with the outdoor temperature ranging from 30 °C to 35 °C and relative humidity of 50% ± 10% to simulate the on-site environment. Runs with high unconfined compressive strength (UCS) and short setting times were observed to have a low water-to-solids (W/S) ratio. All runs with a UCS greater than 20 MPa had a W/S ratio of 0.2, and the runs with the lowest UCS had a W/S of 0.4. The initial setting time for design mixes with a W/S ratio of 0.2 ranged from 8 to 105 min. Meanwhile, five out of seven design mixes with a W/S ratio of 0.4 took longer than 1440 min to set. Specimens with an alkali activator ratio (NaOH/WG) of 0.5 (1:2) and 0.4 (1:2.5) also had significantly lower setting times than those with an alkali activator ratio of 1. The RSM model was verified through confirmatory tests. The results of the confirmatory tests are agreeable, with deviations from the expected UCS ranging from 0 to 38.12%. The generated model is a reliable reference to estimate the UCS and setting time of low-calcium FA geopolymer paste for in situ applications.

scholarly journals Investigation of Portland cement composites containing high amounts of different kinds of fly ashes

2019 ◽  
Author(s):  
Iwona Wilińska ◽  
Barbara Pacewska ◽  
Wojciech Kubissa
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Setting Time ◽  
Cement Composite ◽  
Fly Ashes ◽  
Cement Pastes ◽  
Initial Setting Time ◽  
Initial Setting ◽  
Lower Heat ◽  
The Impact

Utilization of fluidized fly ash in cement composite is problematic, e.g. because of its changeable chemical composition and increased water demand of the mixture. However, this kind of by-product shows some self-cementing properties, which may be beneficial for low-cement mixtures. The article compares the impact of various kinds of fly ashes, i.e. fluidized fly ash and conventional one, and their mixtures on hydration of fly ash–cement compositions in relation to properties of final material. The amount of fly ash in the binder was 50 wt%. Calorimetry, thermal analysis (TG/DTG) and infrared spectroscopy were used. Compressive strength and water absorption of hardened composites were also registered. It was found that both fly ashes exhibit delay effect in fly ash-cement pastes which causes extension of initial setting time and lower heat released compared to the reference without fly ash. At later hydration days, fluidized fly ash develops higher pozzolanic activity than conventional one. Compositions with fluidized fly ash show better compressive strength compared to those containing conventional one. Mixing of different materials of high and low activity (fluidized and conventional fly ash in this case) seems to be a good way for creation of new cement replacement material.

Influence of Triethanolamine on the Properties of Cement-Based Materials

2017 ◽  
Vol 898 ◽  
pp. 2010-2017 ◽  
Author(s):  
Xiao Ying Wang ◽  
Ming Zhang Lan ◽  
Wei Fang Hou ◽  
Bin Feng Xiang ◽  
Xu Dong Zhao
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Cement Hydration ◽  
Setting Time ◽  
Cementitious Materials ◽  
Hydration Products ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
Retarding Effect ◽  
Initial Setting

The effects of triethanolamine on the compressive strength and setting time of fly ash cementitious materials, slag cementitious materials, and limestone cementitious materials were investigated. The results show that the dosage of 0.04% of triethanolamine can significantly improve the 3d, 7d and 28d compressive strength of fly ash cementitious materials. It possesses less impact on the setting time. The dosage of 0.04% of triethanolamine can significantly improve the 3d and 7d compressive strength of slag cementitious materials while the effect of late strength is not obvious. It extends the initial setting time and the final setting time is not changed, which has retarding effect. The results of hydration heat and XRD show that triethanolamine extends the induction period of cement hydration, and gypsum is exhausted in advance during the hydration process. Triethanolamine promotes the transformation of AFt to AFm and there is no effect on the type of hydration products.

Compressive Strength and Setting Time Modification of Class C Fly Ash-Based Geopolymer Partially Replaced with Kaolin and Metakaolin

2018 ◽  
Vol 766 ◽  
pp. 157-163 ◽  
Author(s):  
Khanthima Hemra ◽  
Shuntaro Yamaguchi ◽  
Takaomi Kobayashi ◽  
Pavadee Aungkavattana ◽  
Sirithan Jiemsirilers
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Calcium Oxide ◽  
Setting Time ◽  
Xrd Analysis ◽  
Raw Material ◽  
Initial Setting Time ◽  
High Calcium ◽  
Initial Setting ◽  
Class C

Class C fly ash is widely used as a geopolymer raw material. It contains high calcium oxide and iron oxide resulting in a fast setting property. The influence of using kaolin and metakaolin replaced class C fly ash in geopolymer processing were investigated in term of compressive strength and setting time. Kaolin and metakaolin which calcined at different temperature of 600°C and 700°C replaced Class C fly ash between 0 to 50 wt. %. The geopolymers were prepared at constant KOH concentration as 6.0 M, K2SiO3/KOH ratio as 1.0, solid/liquid ratio as 1.5 and 7 days of curing. The compressive strength is obviously increased when fly ash was replaced with both kinds of metakaolin, although, it is inclined to decrease when replaced by kaolin. The compressive strength is increased up to 13% and 47% with the replacement by 50 wt. % of metakaolin calcined at 600°C and 700°C, respectively. On the other hand, the replacement by 50 wt. % of kaolin give the initial setting time prolonging from about 6 min to 80 min. However, the initial setting time of metakaolin calcined at 600°C and 700°C replacement is also improved to about 37 min and 20 min, respectively. These results from their difference of amorphous phase and reactivity of the replacement materials. XRD analysis reveals the combination phases of amorphous geopolymer gel that is the broad hump centered at 28 – 30° 2θ, and products from the reaction such as calcium oxide, arcanite, calcium silicate hydrate, quartz and muscovite which the two latter are from unreacted metakaolin. They are confirmed by FT-IT result and microstructure evaluation by SEM. Therefore, the partially replacement of fly ash with kaolin and metakaolin in fly ash-based geopolymer production are affected to the compressive strength and resulted to modify the setting time.

scholarly journals Using an Artificial Neural Network to Validate and Predict the Physical Properties of Self-Compacting Concrete

2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
K. Thirumalai Raja ◽  
N. Jayanthi ◽  
Jule Leta Tesfaye ◽  
N. Nagaprasad ◽  
R. Krishnaraj ◽  
...  
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Compressive Strength ◽  
Concrete Strength ◽  
Setting Time ◽  
Second Phase ◽  
Self Compacting Concrete ◽  
Initial Setting Time ◽  
Artificial Neural ◽  
Artificial Neural Network Ann

SCC (self-compacting concrete) is a high-flowing concrete that blasts into structures. Many academics have been interested in using an artificial neural network (ANN) to forecast concrete strength in recent years. As a result, the goal of this study is to confirm the various possibilities of using an artificial neural network (ANN) to detect the features of SCC when Portland Pozzolana Cement (PPC) is partially substituted with biowaste such as Bagasse Ash (BA) and Rice Husk Ash (RHA) (RHA). Specialist systems based on the fully connected cascade (FCC) architecture in artificial neural networks (ANN) are used to estimate the compressive toughness of SCC. The research results are confirmed with the forecasting results of ANN utilizing 73 trial datasets of differentiation focus proposals of cement, BA, and RHA containing parameters such as initial setting time (IST), final setting time (FST), and standard consistency. Experiments to determine compressive strength for a wider range of mixed prepositions will result in higher project expenses and delays. So, an expert system ANN is used to find the standard consistency, setting time, and compressive strength for the intermediate mix propositions according to IS 10262:2009. The experimental results of compressive strength for 28 days are considered, in which 70% was used to train the ANN and 30% was utilized for testing the accuracy of the predicted compressive strength for the intermediate mix proposition. Using all of the datasets, the number of hidden layers used for compressive strength prediction for intermediate mix proposal is determined in the first step. The compressive strength for the intermediate mix preposition was identified in the second phase of the research, using the number of hidden layers determined in the first phase. The results were validated using the correlation coefficient (R) and root mean square error (RMSE) obtained from ANN, resulting in an acceptance range of 97 percent to 99 percent.

scholarly journals Potential of Stainless Steel Slag Waste in Manufacturing Self-Compacting Concrete

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2049
Author(s):  
Julia Rosales ◽  
Francisco Agrela ◽  
José Antonio Entrenas ◽  
Manuel Cabrera
Keyword(s):  
Stainless Steel ◽  
Construction Material ◽  
Steel Slag ◽  
Chemical Properties ◽  
Self Compacting Concrete ◽  
Stainless Steel Slag ◽  
Limestone Filler ◽  
Physical And Chemical ◽  
Slag Waste ◽  
And Chemical Properties

The volume of slags generated from the steel industry is a source of possible resources which is constantly increasing. Specifically, in the production of stainless steel, specific and singular slags with unique characteristics are obtained, which allows considering an approach aimed at their use in new recycling ways. This work shows the feasibility of using stainless steel slag as a substitute for limestone filler in the manufacture of self-compacting concrete. The influence of different treatments applied to slags on physical and chemical properties was studied. On the other hand, the mechanical behaviour, as well as the durability acquired in self-compacting concrete, has been analysed. Very encouraging results were obtained, since this research demonstrates the possible application of this stainless steel slag as a construction material, improving sustainability and promoting circular economy processes, which are achieved through the minimisation of the waste disposal and accumulation.

scholarly journals Effect of Calcium Nitrate on the Properties of Portland–Limestone Cement-Based Concrete Cured at Low Temperature

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1611
Author(s):  
Gintautas Skripkiūnas ◽  
Asta Kičaitė ◽  
Harald Justnes ◽  
Ina Pundienė
Keyword(s):  
Compressive Strength ◽  
Cement Paste ◽  
Setting Time ◽  
Calcium Nitrate ◽  
Curing Temperature ◽  
Hardened Concrete ◽  
Cement Pastes ◽  
Initial Setting Time ◽  
Initial Setting ◽  
Early Strength

The effect of calcium nitrate (CN) dosages from 0 to 3% (of cement mass) on the properties of fresh cement paste rheology and hardening processes and on the strength of hardened concrete with two types of limestone-blended composite cements (CEM II A-LL 42.5 R and 42.5 N) at different initial (two-day) curing temperatures (−10 °C to +20 °C) is presented. The rheology results showed that a CN dosage up to 1.5% works as a plasticizing admixture, while higher amounts demonstrate the effect of increasing viscosity. At higher CN content, the viscosity growth in normal early strength (N type) cement pastes is much slower than in high early strength (R type) cement pastes. For both cement-type pastes, shortening the initial and final setting times is more effective when using 3% at +5 °C and 0 °C. At these temperatures, the use of 3% CN reduces the initial setting time for high early strength paste by 7.4 and 5.4 times and for normal early strength cement paste by 3.5 and 3.4 times when compared to a CN-free cement paste. The most efficient use of CN is achieved at −5 °C for compressive strength enlargement; a 1% CN dosage ensures the compressive strength of samples at a −5 °C initial curing temperature, with high early strength cement exceeding 3.5 MPa but being less than the required 3.5 MPa in samples with normal early strength cement.

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