Slag Based Geopolymer Concrete Research Articles

Properties of blast furnace slag geopolymer concrete

Cement being the most consumed commodity after water contributes about 8% CO2 to the total amount of CO2 emitted. Therefore, alternate binders are being explored to make concrete production more sustainable. Geopolymer an inorganic polymer is being projected as one of the potential alternatives. However, most of the published literature recommend the use of highly concentrated alkali hydroxides of sodium or Potassium as alkali activator or a combination of alkali hydroxide with silicates for geopolymer synthesis, which are unsafe for workers. Furthermore, heat curing regimes of 24 to 120 h at temperature ranging 60 to 85 °C are also recommended. However, heat curing of structural components in a building is not possible in most of the in-situ construction projects, except for the production of prefabricated structural components. Furthermore, the silica and alumina rich wastes are preferred choice as the precursor for geopolymer synthesis. Therefore, an experimental study is carried out to produce blast furnace slag based geopolymer concrete using sodium silicate as the alkali solution. The geopolymer concrete was cured for 7, 14 and 28 days at ambient temperature to assess the mechanical properties of the developed concrete. The results of compressive and flexural strength test indicate the possibility of making ambient cured geopolymer concrete using sodium silicate and granulated blast furnace slag for structural application.

Influence of Slag-Based Geopolymer Concrete on the Seismic Behavior of Exterior Beam Column Joints

In reinforced concrete (RC) constructions, the beam-column junctions are very sensitive to lateral and vertical loads. In the event of unforeseen earthquake and wind loads, this insufficient joint performance can lead to the failure of the entire structure. Cement industries emit a large amount of greenhouse gases during production, thus contributing to global warming. The nature of cement concrete is fragile. Cement output must be reduced in order to ensure environmental sustainability. Geopolymer concrete (GC), which is a green and low-carbon material, can be used in beam-column joints. M30 grade BBGC was developed and employed in the current study. Alkaline liquids are produced when sodium silicate and sodium hydroxide are mixed at room temperature. The alkaline liquid to fly ash ratio was fixed at 0.5, and the concentration of NaOH was fixed at 8 M. The mechanical properties of the Binary Blended Geopolymer concrete (BBGC), containing fly ash and GGBS, at proportions ranging from 0% to 100%, were investigated. This study was further expanded to examine the behavior of two groups of binary blended geopolymer concrete (BBGC) exterior beam-column joints, with cross sections of 230 mm × 120 mm and 170 mm × 120 mm. The column heights and lengths were both 600 mm under reverse cyclic loads in order to simulate earthquake conditions. The failure mechanism, ductility, energy absorption capacity, initial crack load, ultimate load carrying capacity, and structural performance was evaluated. The test findings showed that BBGC with 20% fly ash and 80% GGBS had the highest compressive strength and split tensile strength. When compared with other beam column joints, those containing 20% fly ash and 80% GGBS performed better under cyclic loading. The test findings imply that GGBS essentially enhances the joint performance of BBGC. The microstructural SEM and EDS studies revealed the reasons behind the improvement in strength of the GGBS fly ash-based Geopolymer concrete.

Fracture behavior of slag & fly ash-based geopolymer concrete in comparison with opc-based conventional concrete, including the effect of steel and hybrid fibers

The study presents an experimental investigation of the fracture behavior of hardened slag and fly ash-based alkali-activated normal and high-strength geopolymer concrete compared with conventional Ordinary Portland Cement (O.P.C.) based concrete with steel and hybrid fibers. The fracture parameters considered in the experimental investigation include fracture energy, stress intensity factor, energy release rate, and characteristic length. The study concludes that the observed differences in conventional and geopolymer concrete's fracture and mechanical performance agree with the microstructural differences between these concrete systems reported in past literature. The slag-based geopolymer concrete is marginally inferior to the O.P.C.-based concrete, with similar compressive strength in fracture performance. Also, hybrid fiber reinforcement improves the fracture performance of geopolymer concrete more than steel fiber alone. Contrary to geopolymer concrete, steel fiber reinforced conventional concrete is superior to hybrid fiber reinforced conventional concrete in terms of fracture behavior.

Studies of polypropylene fibres’ effect on strength and workability of slag based geopolymer concrete

The most useful, desirable, adaptable, emerging, reliable, and enduring construction material is concrete. After water Concrete is the most usable substance, and it requires a lot of Cement. The source of carbon dioxide pollution in the atmosphere, after the automobile is due to production of Ordinary Portland Cement and additionally, a significant quantity of energy was used to produce cement. The replacement of OPC or elimination of OPC in concrete is very much important to avoid global warming; A novel construction material called geopolymer concrete is created through the chemical reaction of inorganic molecules. The by-product of coal from a thermal power plant known as fly ash is widely accessible worldwide. Flyash is abundant in alumina and silica. This paper is aimed at studies on the strength and workability of conventional and geopolymer concrete. G40 grade of geopolymer concrete, which equivalent to M40 grade of conventional concrete has been developed by conducting various mixes. The conventional concrete specimen are casted and cured in water and in geopolymer concrete, these are cured with the help of oven for one day after one day rest period and rest of the days kept in atmosphere until testing. The test results have shown that the compressive strength is increased and workability is decreased with the addition of polypropylene fibres.

Investigation of Compressive Strength of Slag-based Geopolymer Concrete Incorporated with Palm Oil Fuel Ash

The paper investigated the compressive strength of ground granulated blast furnace slag-based geopolymer concrete incorporated with palm oil fuel ash compared to portland limestone cement concrete. An appropriate geopolymer mix design was first determined. This mix entailed fine aggregates: coarse aggregates: cementitious material: liquid ratio of 2: 2.5: 1: 0.5, respectively, with 100% replacement of portland cement with ground granulated blast furnace slag (GGBS) incorporated with palm oil fuel ash (POFA). An alkaline solution was used in place of water containing sodium hydroxide and sodium silicate. Following this design, five geopolymer mixes were prepared, each of varying POFA-GGBS ratios of 0:100, 25:75, 50:50, 75:25, and 100:0, and a 14M alkaline solution was used. In addition, a control mix was determined, comprising 100% portland limestone cement (PLC) as the cementitious material and 100% water. Three cubic samples were casted for each geopolymer mix with the control mix, and then the geopolymer mixes were thermally cured for 24 hours. The compressive strength test was conducted on the test samples after ambient curing of 7 days and 28 days, and values for compressive strength (MPa) and failure load (KN) were recorded. Through comparative analysis, it was determined that the most efficient geopolymer mix was mix 2 of GGBS: POFA ratio of 75:25 with 14M alkaline solution. Mix 2 achieved the highest compressive strength of 65.41MPa, approximately 21.99% higher than the strength attained by portland cement concrete samples, measured to be 53.62MPa. Thus, geopolymer concrete can achieve greater strength than portland cement concrete. Keywords: Alkaline solution, Geopolymer concrete, cementitious material, ground granulated blast furnace slag, compressive strength, palm oil fuel ash

Experimental study of compressive strength, permeability and impact testing in geopolymer concrete based on Blast furnace slag

Cement production has always been associated with environmental challenges due to carbon dioxide emissions. On the other hand, cement production is an energy-intensive process and leads to the consumption of abundant fossil fuels. In order to solve this problem, the production of geopolymer concrete is on the agenda. The researchers decided to reduce the negative effects of cement production and have superior properties than ordinary concrete. In the current study, slag-based geopolymer concrete was used with 0-2% polyolefin fibers and 0-8% nano-silica to improve its structure. After curing the specimens under dry conditions at a temperature of 60°C in an oven, they were subjected to compress strength, tensile strength and Drop weight hammer tests to evaluate their mechanical properties, as well as Permeability test to assess their durability. tests were performed at 7 and 90 days of age at ambient temperature (20℃). The addition of nano-silica enhanced the whole properties of the slag-based geopolymer concrete. Increasing the curing age improved the results of all tests. The results of all tests in geopolymer concrete showed the superiority of the results over conventional concrete. At the 28-day curing age, the addition of up to 8% nanosilica to the geopolymer concrete composition improved the compressive strength test results by 19.01%, water permeability by up to 35% and impact strength by up to 36.36%. Addition of up to 2% of polyolefin fibers in the composition of geopolymer concrete resulted in a 28.95% decrease in compressive strength but a 20% improvement in water permeability and an 8.26-fold increase in impact strength. In the following, by conducting the SEM test, a microstructure investigation was carried out on the concrete samples. In addition to their overlapping with each other, the results indicate the geopolymer concrete superiority over the regular concrete. Besides, it demonstrated the positive influence of nano-silica addition on the concert microstructure.

Deep long short-term memory (LSTM) networks for ultrasonic-based distributed damage assessment in concrete

This paper presented a comprehensive study on developing a deep learning approach for ultrasonic-based distributed damage assessment in concrete. In particular, two architectures of long short-term memory (LSTM) networks were proposed: (1) a classification model to evaluate the concrete’s damage stage; (2) a regression model to predict the concrete’s absorbed energy ratio. Two input configurations were considered and compared for both architectures: (1) the input was a single signal; (2) the inputs were four signals from four sides of the specimen. A comprehensive experimental study was designed and conducted on ground granulated blast furnace slag-based geopolymer concrete, providing a total number of 1920 ultrasonic signals from different damage stages. Unsupervised k-means clustering based on dynamic time warping (DTW) was implemented to cluster the ultrasonic response signals from the experimental study into five defined damage stages. The proposed LSTM architectures were successfully trained and validated using the experimental dataset. Moreover, the performance of the LSTM models was evaluated in noisy environments. The proposed LSTM models in this study used the time series of response signals for damage assessment. Therefore, the damage-sensitive features were automatically extracted by the LSTM layers. For comparison, a set of linear and nonlinear ultrasonic features were manually extracted from the response signals as damage-sensitive features, and their sensitivity to damage was investigated. Artificial neural networks were implemented to combine the extracted features and perform the same tasks defined for LSTM models. Comparing the two approaches showed that using the time series of ultrasonic response signals as the input of LSTM models outperforms the idea of using the manually extracted features. This study showed that the presented method is efficient, reliable, and promising for nondestructive evaluation of damage in concrete.

Bond and anchorage performance of beam flexural bars in beam-column joints using slag-based geopolymer concrete and their effect on seismic performance

An available study on the bond and anchorage performance of beam flexural bars in beam-column joints using slag-based geopolymer concrete (GC) is limited. The applicability of current design codes to beam flexural bars design in GC beam-column joints is unknown. In this study, to investigate the bond and anchorage performance of beam rebars at the GC beam-column joints and their effect on seismic performance, cyclic loading tests were performed on 2 reinforced GC interior beam-column joints and 6 reinforced GC exterior beam-column joints. The test results showed that the increase in column depth-to-beam rebar diameter ratio (hc/db) from 21 to 25 improved the bond performance of the beam flexural bars in the reinforced GC interior beam-column joints, which significantly improved the energy dissipation capacity. The limits of hc/db larger than 20 in GB50010-2010 (except seismic grade I that requires hc/db ≥ 25) and ACI 318-19 were not safe for reinforced GC interior beam-column joints. The limits of hc/db in Eurocode 8 and NZS3101 for low-strength concrete (fc′ ≤ 30 MPa) were applicable. In reinforced GC exterior beam-column joints, the bond and anchorage performance of 90˚ hooked bars was superior to that of the corresponding headed bars. Regardless of the anchorage details, the bond and anchorage performance of the reinforced GC exterior beam-column joints increased with the increase of the development length of beam flexural bars. In reinforced GC exterior beam-column joint design, the bar development length requirement of GB50010-2010 was applicable to both 90˚ hooked bars and headed bars. Eurocode 8, NZS3101, and ACI 318-19 were applicable to the development length of 90˚ hooked bars.

Experimental evaluation of compressive, tensile strength and impact test in blast furnace slag based geopolymer concrete, under high temperature

Today, the use of nanoscale additives in the concrete industry with the aim of reducing the negative effects of Portland cement and improving the mechanical properties of concrete has received much attention. Also, in order to reduce the harmful environmental effects and increase the mechanical properties and durability of concrete, particles with high pozzolanic properties are used as a suitable alternative to ordinary cement in concrete. In this regard, geopolymer concrete using materials containing aluminosilicate materials with adhesive properties and filler, as an alternative to cement, has attracted the attention of researchers. Concrete resistance to high heat is of particular importance. Geopolymer concrete has a good performance against heat due to its strong structure. In the current study, slag-based geopolymer concrete was used with 0-2% polyolefin fibers and 0-8% nano-silica to improve its structure. After curing the specimens under dry conditions at a temperature of 60°C in an oven, they were subjected to Compressive strength, Tensile strength, and Drop weight hammer tests to evaluate their mechanical properties. all tests were performed at 90 days of age under ambient temperature (20 ℃) and high temperature (500 ℃). The addition of nano-silica enhanced the whole properties of the slag-based geopolymer concrete. Addition of up to 8% nanosilica to the geopolymer concrete composition at 20% temperature improved the compressive strength test results up to 21.94%, tensile strength up to 15.19% and impact energy up to 36.36%. Addition of up to 2% of polyolefin fibers to the geopolymer concrete composition improved the tensile strength up to 11.76%, the impact energy up to 8.26 times and the compressive strength drop up to 22.49%. Applying high heat to geopolymer concrete samples reduced the compressive strength up to 16%, tensile strength up to 21% and impact energy up to 72.72%. The effect of heat on the drop in results in control concrete is more than geopolymer concrete. In the following, by conducting the SEM test, a microstructure investigation was carried out on the concrete samples. In addition to their overlapping with each other, the results indicate the geopolymer concrete superiority over the regular concrete. Besides, it demonstrated the positive influence of nano-silica addition on the concert microstructure.

Experimental study of the effects of adding silica nanoparticles on the durability of geopolymer concrete

ABSTRACT The advantages of using geopolymer materials instead of cement in concrete are not limited to high durability properties. geopolymer concrete was introduced to mitigate the environmental damages caused by CO2 emissions and the great level of fossil fuels consumption during cement manufacturing. In the present investigation, a number of experimental studies were conducted on slag-based geopolymer concrete. Accordingly, nano-silica particles were used to improve the geopolymer concrete structure’s matrix. In the current study, slag-based geopolymer concrete was used with 0–2% polyolefin fibres and 0–8% nano-silica. They were subjected to water absorption and permeability tests to assess their durability. The addition of nano-silica enhanced the whole properties of the slag-based geopolymer concrete. By using the nano-silica, the concrete paste microstructure became denser and more homogeneous, and the pores decreased. The compressive strength and tensile strength of the concrete increased by up to 22% and 14% respectively. On the other hand, in terms of durability, the nano-silica lowered the water absorption and permeability coefficients by up to 24% and 44%, respectively, by filling the pores of the concrete. In the weight loss test, geopolymer concrete achieved superior results (up to 16%) compared to ordinary concrete.

Effect of nano titanium di oxide on mechanical properties of fly ash and ground granulated blast furnace slag based geopolymer concrete

In current scenario, new innovative recyclable materials are scientifically tried to be a part of concrete for improving the properties and reducing the cost. The aim of the present study, is to evaluate the mechanical properties of Fly ash Ground Granular Blast Furnace Slag based Geopolymer Concrete (FGGPC), with partial replacement of fly ash by various percentage of Titanium di oxide (TiO2). In this study, mechanical properties like strength (compressive and split tensile strength) and elasticity properties (modulus of elasticity and modulus of rupture) are assessed, which is basic requirement study for any type of concrete. It is found that, up-to 3% partial replacement of fly ash by TiO2 result in enhanced mechanical properties of FGGPC. Models based on mechanical properties of conventional concrete are available in literatures and standards. Dependency of these models are checked using statistical method and interval concepts. Reliability of the relationships between conventional and FGGPC is validated by Integral Absolute Error (IAE), Mean Absolute Error (MAE), Root Mean Square Error (RMSE), prediction and confidence intervals concepts.

Influence of solution binder ratio on behaviour of Ground Granulated Blast-Furnace Slag based Geopolymer Concrete

In recent years the word sustainability has become a priority of many researchers. In this regard, many evolutions were put forth in the concrete industry one of them is Geopolymer concrete. Ground granulated blast furnace slag (GGBS) is used as source material which is rich in alumina and silica contents, which forms alumina silicate gel when mixed with an alkali solution of sodium hydroxide and sodium silicate which then binds with aggregate. Till now many researchers had done research on Geopolymer concrete using Fly ash as major binding material. Literature is also available on Geopolymer concrete with GGBS as major binding material but the behaviour of Geopolymer concrete was not studied widely by varying solution binder ratio. In this research, the behaviour of GGBS based Geopolymer concrete was studied, by replacing fly ash with 0%, 10%, 20% and 30% and varying solution/binder (s/b) ratio 0.3, 0.4, 0.5 and 0.6. The mix proportions were prepared by taking a ratio of 1:1:3 by weight and all the specimens were cured at ambient temperature. Mechanical properties such as compressive strength, tensile strength and flexure strength were determined. A sulphate attack test was also conducted. As quantity of FA increased, strength decreased.

Punching shear behavior of geopolymer concrete two-way flat slabs incorporating a combination of nano silica and steel fibers

This research was conducted by performing center point load tests on the two way flat slab samples to investigate the combined effects of steel fiber (SF) and Nano-silica (NS) on the punching shear and deflection capacities of ten slag-based Geopolymer Concrete (GC). This study consists of two parts; in the first part, the effects of only SFs were investigated, while in the second part the combined effects of NS and SFs on the properties of GC were examined. During the study, two types of hook-end SFs (0.5% and 1%) and only 2% NS were used. The tested slabs showed that the energy absorption capacity/toughness of GC slabs was positively affected by the inclusion of NS and SFs. Also, it was favorably influenced by SFs content and aspect ratio. Furthermore, these slabs were categorized. While, NS and SFs enhanced the punching shear strength of the slabs, the combined influence of NS and SFs exhibited better the punching shear capacity compared to individual utilization. It is clear from the experimental studies that the slab with the combination of NS and SF2 outperformed all of them and showed 131.08% higher strength bearing capacity than the slab without SFs and NS.

Compressive behavior and stress-strain model of square confined ambient-cured fly ash and slag-based geopolymer concrete

Although a great deal of work has been completed towards the study on geopolymer concrete (GC), most of the efforts have focused on the material mechanical behavior. The objective of this paper is to present the results of an experimental study aimed to investigate the stress-strain behavior of confined fly ash and slag-based GC (FASGC) through the compression testing of a total of fourteen square ambient-cured short columns. The experimental results indicated that the increase in the slag content resulted in higher unconfined compressive strength but more obvious brittle property of confined FASGC. The effectiveness of lateral steel confinement was higher for FASGC than that for ordinary Portland cement-based concrete (OPCC), despite the lateral confinement index Kn of the former one was a little smaller compared to the latter one, the maximum differences in both fcc/fc0 and εcc/εc0 between them were 20.8% and 59.3%, respectively. Both fcc/fc0 and εcc/εc0 were not strongly related to the variation of the spacing of transverse reinforcement. The increase in the diameter of transverse reinforcement was not obviously improve the fcc/fc0 but resulted in the increase in the εcc/εc0, nonetheless, the εcc/εc0 was only increased by 70.9% as the Kn increased 3 times. The models were proposed to predict both ultimate stress and strain and to describe the stress-strain behavior of FASGC with good accuracy, more test data is further need to refine the proposed models. In light of the results, it is recommended to further investigate the effect of the fibers such as steel fiber, FRP fiber on the improvement of the brittle behavior of FASGC.

Influence of mixture design parameters on the static and dynamic compressive properties of slag-based geopolymer concrete

This study investigated the influences of water-to-binder mass ratio (0.44, 0.47, and 0.50), and waterglass (8%, 12% and 16%) and fly ash (0%, 25% and 50%) contents on the slump, cubic compressive strength, and static and dynamic compressive behaviors of slag-based geopolymer concrete (GC). Static compressive tests were carried out by using an electro-hydraulic servo-controlled compressive test system, and dynamic ones were performed by using a split Hopkinson pressure bar (SHPB) apparatus. The specimens with a wide range of the compressive strength (from 50 MPa to 80 MPa) were prepared. The results show that the workability of fresh slag-based GC increased with increasing water-to-binder ratio, and waterglass and fly ash contents. The cubic compressive strength increased with the decreases of water-to-binder ratio and fly ash content, and the increase of the waterglass content. Increasing waterglass content contributed to the improvement of the static compressive behavior of slag-based GC, such as elastic modulus and peak stress, while it led to the rise of the brittleness. Slag-based GC with different water-to-binder mass ratios, and waterglass and fly ash contents showed a strong strain-rate dependency. However, the inclusion of 50% fly ash induced a sharp increase of the dynamic compressive strength and dynamic increase factor (DIF) at a high strain rate. Moreover, both the two formulations for fitting static compressive stress-strain curve and DIF with higher accuracy were proposed in this study.

Evaluation of the Effect of Granite Waste Powder by Varying the Molarity of Activator on the Mechanical Properties of Ground Granulated Blast-Furnace Slag-Based Geopolymer Concrete.

Industrial waste such as Ground Granulated Blast-Furnace Slag (GGBS) and Granite Waste Powder (GWP) is available in huge quantities in several states of India. These ingredients have no recognized application and are usually shed in landfills. This process and these materials are sources of severe environmental pollution. This industrial waste has been utilized as a binder for geopolymers, which is our primary focus. This paper presents the investigation of the optimum percentage of granite waste powder as a binder, specifically, the effect of molar and alkaline to binder (A/B) ratio on the mechanical properties of geopolymer concrete (GPC). Additionally, this study involves the use of admixture SP-340 for better performance of workability. Current work focuses on investigating the effect of a change in molarity that results in strength development in geopolymer concrete. The limits for the present work were: GGBS partially replaced by GWP up to 30%; molar ranging from 12 to 18 with the interval of 2 M; and A/B ratio of 0.30. For 16 M of GPC, a maximum slump was observed for GWP with 60 mm compared to other molar concentration. For 16 M of GPC, a maximum compressive strength (CS) was observed for GWP with 20%, of 33.95 MPa. For 16 M of GPC, a maximum STS was observed for GWP, with 20%, of 3.15 MPa. For 16 M of GPC, a maximum FS was observed for GWP, with 20%, of 4.79 MPa. Geopolymer concrete has better strength properties than conventional concrete. GPC is $13.70 costlier than conventional concrete per cubic meter.

Strength and Microstructural Characterization of Ferrochrome Ash- and Ground Granulated Blast Furnace Slag-Based Geopolymer Concrete

Strength and Microstructural Characterization of Ferrochrome Ash- and Ground Granulated Blast Furnace Slag-Based Geopolymer Concrete

Investigation on the effect of ultra fine rice husk ash over slag based geopolymer concrete

Investigation on the effect of ultra fine rice husk ash over slag based geopolymer concrete

Synthesis of Fly-ash and Slag Based Geopolymer Concrete for Rigid Pavement

This research work describes the synthesis of fly-ash and granulated blast furnace slag (GGBS) based Geopolymer concrete (FSGC) for paving applications. The study looked at a total of 12 combinations comprising GGBS in proportions of 25%, 50%, 75%, and 100% as a fly-ash substitute, sodium hydroxide (NaOH) solutions of 8, 10, and 12 molars(M), and a fixed sodium hydroxide solution to sodium silicate (S/S) ratio of 2.5. The specimens were all cured outside in the open air. The investigation found that when the GGBS content and NaOH molar concentration increase, the mix's consistency stiffens, resulting in zero slumps and making it harder to work with. At the same time, as the GGBS content and NaOH molarity increased, the mechanical strengths of SFGC mixes improved. Maximum mechanical strengths were achieved using a mixture of 100 percent GGBS and 12 M NaOH solution. According to the findings of the study, the SFGC mix with GGBS content ranging from 25% to 30% and NaOH molarity ranging from 8 M to 10 M is adequate for meeting the criteria of paving grade concrete standards.

Effect of sea sand and recycled aggregate replacement on fly ash/slag-based geopolymer concrete

Abstract The purpose of this study is to investigate the impact of recycled aggregate (RA) and sea sand (SS) replacement on fly ash (FA) slag-based geopolymer concrete (GPC). An orthogonal array design is employed to obtain the optimum mix proportions, and geopolymer mixes are prepared using slag percentages of 10%, 20%, and 30% slag in FA/slag-based GPC. Sodium hydroxide (NaOH) solution is prepared at three concentrations (8 mol/L, 12 mol/L, and 16 mol/L). The mechanical properties of the geopolymer mixes are determined based on the tensile strength, compressive strength, flexural strength, and elastic modulus. GPC is prepared using water-binder ratios of 0.3, 0.4, and 0.5 at 0%, 25%, 50%, 75%, and 100% of RA replacement. The results showed that the variation in the RA replacement ratio had little effect on the strength and elastic modulus of sea sand geopolymer concrete (SS–GPC), but it had a significant effect on river sand geopolymer concrete (RS–GPC). The RA replacement ratio also showed a noticeable change in the damage surface of the specimens. In addition, SS hinders the hydration reaction of the geopolymer in the early stage and reduces the early strength of the GPC; however, in the later stages, the effect becomes insignificant.