Effect Of Superabsorbent Polymer Research Articles

Effect of super absorbent polymer mixing method on shrinkage performance of cast-in-place concrete confined by existing concrete

To study the effect of different super absorbent polymer (SAP) mixing methods on mechanical and shrinkage properties of internal curing concrete, SAP mixing mode was used as the study variable, and simulated the bridge leveling structure. The flow performance test, mechanical performance test, free shrinkage test, restrained shrinkage test and scanning electron microscope observation test were carried out on the internal curing concrete. The influence of different mixing methods on the flow properties, mechanical properties, shrinkage properties and microstructure of internal curing concrete were analyzed. The results showed that the amount of mixing water had a great influence on the fluidity when adding pre-absorbent SAP; The effect of SAP on the mechanical properties is minimal when the dosage is 0.2% of the mass of cementing material; Pre-absorbent SAP has the best effect on improving shrinkage cracks of concrete; SAP stored water at the initial stage of hydration, promoted the generation of hydrolysis products, prolong the hydration process, filled the gap inside the concrete, and improved the anti-cracking performance. It is recommended that SAP should be partially pre-absorbed.

Effect of Superabsorbent Polymer (SAP) Size on Microstructure and Compressive Strength of Concrete.

Superabsorbent polymers (SAPs) are hydrophilic, polymeric network materials renowned for their ability to enhance various properties of cementitious materials. This investigation examines the impact of SAP size on the hydration degree, porosity, and compressive strength of cement pastes and concrete under diverse curing conditions and ageing periods. The findings reveal that SAP addition stimulates the hydration of the C2S phase, particularly during the early curing stages, thereby favouring early strength development. However, the effect of SAPs on hydration promotion diminishes as their size increases. Conversely, the size of SAPs affects the hydration range of their action, and the 400 µm SAP demonstrates the most extensive range of hydration enhancement, reaching up to 105 µm. Additionally, SAPs effectively reduce porosity in small pores (4 nm-10 μm), with 200 μm and 400 μm SAPs exhibiting the highest efficacy. While analysing the effects of SAPs on larger pores (>10 μm), the results show that although larger SAPs result in larger average porosity, the total porosity is effectively reduced, particularly in samples incorporating 400 μm SAP. The compressive strength of cement paste, even after 28 days, is slightly reduced following the introduction of SAPs. However, the strength of concrete, due to the naturally occurring pores eliminating the negative effects of the pores produced by SAPs, is significantly increased following the introduction of SAPs, especially 400 µm SAP.

Effect of super absorbent polymer (SAP) on volume stability and application performance of cement mortar with accelerator

Shotcrete has high cementitious material content, small aggregate particle size, high setting accelerator content, and is prone to shrinkage and deformation, and there are few studies on the volume stability of shotcrete at present. Super absorbent polymer (SAP) is widely used as an internal curing agent, it has low cost and small dosage usage, but it has not been applied to shotcrete to improve volume stability. In this study, super absorbent polymers with different dosages, particle sizes, and extra water were used. The application performance, volume stability and moisture change of different cement mortars were studied under the condition of 4 % of alkali accelerator or 7 % of alkali-free accelerator. The results show that with the increase of super absorbent polymer dosage, the setting time of cement mortar mixed with accelerator is shortened, the 1-day compressive strength is reduced, and the 28-days compressive strength is on average increased. Among them, 0.4SAPAS (addition of 0.4 % SAP) can reduce the initial and final setting time by 101 s and 154 s. Further, the autogenous and drying shrinkage are reduced, and the internal humidity change and mass loss are slowed down. At the age of 180 days, the autogenous and drying shrinkage of 0.4SAPAS were 51 % and 47 % lower than those of AS-7. The XRD, SEM and hydration temperature test showed that the use of super absorbent polymer slightly delayed the hydration process at early age, the hydration temperature peaks of AS-7,0.2SAPAS and 0.6SAPAS are 38.5 °C, 36.7 °C, and 35.1 °C. But at 28 days, the surrounding cement particles were further hydrated due to the release of water from super absorbent polymer.

Experimental study of lightweight concrete prepared from super absorbent polymers (SAPs) and glass fibers (GF)

ABSTRACT This study investigates the effect of super absorbent polymers (SAPs) and glass fiber (GF) additions on the properties of lightweight concrete. The SAPs act as a pore-forming agent, with the addition of various GF contents (0.1–1.0% by weight of dry ingredients). The results indicate that the use of SAPs at 7% by weight of OPC produces a product with similar properties to conventional lightweight concretes which meet the ASTM C332–17 standard. The addition of GF to the mixture tends to reduce the dry density and compressive strength, but increases the porosity and flexural strength. The results indicate that the use of SAPs at 7% by weight of OPC produces a product with similar properties to conventional lightweight concretes which meet the ASTM C332–17 standard. The 28-day compressive strengths decreased from 7.04 ± 0.07 for control sample to 4.59 ± 0.11 MPa, while the flexural strengths increased from 3.89 ± 0.04 for control sample to 6.72 ± 0.06 MPa. High-porosity lightweight concrete prepared from SAPs and GF shows reduced thermal conductivity and an increased sorption rate. The initial rate of water absorption gradually increases from 2.48 × 10−1 mm/sec0.5 in the sample without GF up to 5.45 × 10−1 mm/sec0.5 in the sample containing 1.0 wt.% GF. Comparison with the literature indicates that the use of SAPs as pore-forming agents in conjunction with GF has the potential to produce fiber-reinforced lightweight concrete with improved properties.

Effect of superabsorbent polymers and expansive agent on the properties and microstructures of self-stressing high performance concrete

In order to overcome the self-desiccation and high autogenous of high performance concrete (HPC), the superabsorbent polymers (SAP) and expansive agent (EA) are considered to be compositely incorporated, which has great significance to the HPC structures. This paper presents an experimental study on the compounded effect of SAP and EA on the properties of HPC. The workability, internal relative humidity (IRH), compressive strength and free expansive ratio as well as self-stress of HPC were examined. The influencing mechanism of SAP and EA on HPC was discussed. The results showed that the compressive strength of HPC generally decreases with the increases of EA and SAP contents and additional water ratio. The water release of SAP particles mainly occurs at 7–10 d to maintain a high IRH. The higher EA content induces the larger free expansive ratio and self-stress, caused by the increased hydration products of Aft and Ca(OH)2 bulks. For a low SAP content of 0.1%, the shrinkage is alleviated, but it becomes even worse for a higher SAP content. The total amount of pores increases with the inclusions of EA and SAP, except for the harm pores. The hydration products caused by EA could fill and compensate the pores left behind by the SAP particles, showing synergetic improvement effect. The self-stress values of HPC in this study are at the range of 2.73–3.44 MPa, From the present study, the SAP content of 0.1% is more recommended for the HPC in real engineering practices.

Evolution and mechanism on shrinkage of high-performance concrete with full aeolian sand cured by superabsorbent polymer

Preparing high-performance concrete with full aeolian sand (FA-HPC) can address the shortage of high-quality aggregates. Its low water-binder ratio (w/b) and high content of cementitious material content endow this concrete with great strength and durability but a high risk of shrinkage cracking. Herein, the effect of superabsorbent polymer (SAP) on the separate shrinkage of FA-HPC, and the mechanism of internal curing (IC) were investigated from various macro–micro perspectives. IC water migration was monitored via nuclear magnetic resonance (1H NMR). The results showed that autogenous shrinkage dominated the total shrinkage of the FA-HPC, accounting for 70%–80%. The SAP with medium particles effectively reduced the total shrinkage in the plastic and hardening stages, with nearly zero autogenous shrinkage at 0.3% content. From the characterization of mechanism, capillary pressure build-up of FA-HPC containing SAP was delayed with significant suppression in internal relative humidity (IRH) drop and moisture loss especially due to self-desiccation. The coupling effect of self-desiccation and evaporation triggered the nonlinear correlation between moisture loss and total shrinkage, whereas SAP amplified the proportion of drying shrinkage. Microscopically, the incorporation of SAP with IC water hindered the early hydration process but resulted in a higher final hydration degree within 72 h bringing a refined pore structure. Moreover, the adaptive release of IC water was used for hydration mainly within 72 h, and it continuously compensated for IRH drop over 28 d based on the supply–demand mechanism in FA-HPC. This study proposes a promising strategy for shrinkage resistance of FA-HPC and promotes the application of aeolian sand-based concrete.

Effect of Super Absorbent Polymer and Ceratophyllum Powder Application on Some Soil Physical Properties

A two factorial laboratory experiment was conducted according to randomized complete block design with three replications, to investigate the effect of super absorbent polymer (SAP) and ceratophyllum powder application on some physical characteristics of loamy sand soil. The first factor included three levels of super absorbent polymer, namely 0,0.2, and 0.4 %. While the second factor consists of three levels of ceratophyllum powder i.e., 0,2, and 4 %. The treated soil (treated with super absorbent polymer and ceratophyllum powder) was exposed to 14 cycles of wetting and drying. Effect of experiments factors on coefficient of linear extensibility, soil bulk density and total porosity were measured. The obtained results show that the super absorbent polymer and ceratophyllum powder application led to increase the dry soil bulk density, total porosity, and the coefficient of linear extensibility values for all application levels. Regarding the soil aggregate stability, a significant increase was observed under effect of super absorbent polymer and ceratophyllum powder application. Where the highest value of soil aggregate stability was recorded at 0.4% level of SAP reached 54.2%. Likewise, the highest value of soil aggregate stability under effect of ceratophyllum powder application reached 30.7% at 4% level of application, compare to the control treatment that gave 11.1 % with increasing rate reached 76.5%. In same direction, all moisture content had increased under effect of study factors. However, the super absorbent polymer was superior to ceratophyllum powder application.

Effect of super absorbent polymer on drought mitigation, and enhancing productivity and profitability of Indian mustard (Brassica juncea L.)

Under the current scenario of increasing demand of edible oil and dwindling irrigation water supply, the development of drought mitigation strategies is the need of the hour to increase productivity and profitability of the Indian mustard (Brassica juncea L.). A field experiment was conducted to evaluate the field efficacy of the superabsorbent polymer (SAP: Pusa hydrogel) and its application rates 0, 1.5, 2.5 and 5.0 kg/ha under moisture stress and normal moisture conditions in a factorial randomized complete block design and replicated thrice. The SCMR, dry matter accumulation, 1000-seed weight, oil and biological yields, economic indicators of the Indian mustard and also the soil available N, P and S contents were reduced (p = 0.05) under moisture stress regime, but improved considerably with the use of SAP. Across the moisture regimes, the maximum oil yield (1.12 t/ha), biological yield (9.24 t/ha), harvest index (29.12 %), gross returns (` 116140/ha), net returns (` 74790/ha), B: C ratio (1.81) and economic efficiency (` 519.4/ha/day) were recorded with SAP @ 5.0 kg/ha. SAP @ 2.5 to 5.0 kg/ha improved oil yield and net returns by 3 % (0.04 t//ha) and 2 % (` 1980/ha), respectively under normal moisture regime, while under moisture stress these parameters were increased by 13% (0.12 t/ha) and 14% (` 8280/ha), respectively. Further, under moisture stress, the maximum B:C ratio (1.66) was recorded with 5.0 kg SAP/ha, while it was the maximum(2.05) with 2.5 kg SAP/ha under the normal moisture regime. Across the moisture regimes, SAP @ 5.0 kg/ha, being on par with 2.5 kg SAP/ha improved the soil organic carbon, available N, P, K and S by 29.27, 13.61, 14.10, 11.95 and 25.01%, respectively over the control. Thus, 5.0 kg SAP/ha under moisture stress and 2.5 kgSAP/ha under normal moisture condition can be recommended for increasing yield, profit, savingwater and better soil health in Indian mustard.

Effect of super absorbent polymers in properties of self-curing concrete – A state of art of review

The strength of concrete mainly depends on the curing of the concrete, but in recent times due to population density, water demand increases day by day. This makes impact in availability of water for curing concrete. To overcome this situation, self-curing or internal curing concept in concrete can be preferred. Internal curing offers benefits of improved hydration, reduced chloride ingress and reduced early age cracking, which help concrete, achieve its maximum potential as a sustainable building material by extending its service life. It may be effectively overcome by way of the usage of self-curing concrete. For this reason, usage Superabsorbent polymer (SAP) as an admixture in diverse grades of concrete to reduce issues during curing, using this super absorbent polymer (SAP) in concrete has been shown to have numerous vital results on concrete structures. The primary benefits of internal curing are more durable and less permeable concrete. Congenial atmosphere would aid the hydration of cement and hence curing of concrete becomes essential till a major portion of the hydration process is completed. The proposed research work in Self Curing Concrete has many advantages when compare to normal concrete in aspect of strength at early stage, reduction in shrinkage crack and its flowable mix without bleeding and segregation etc. Besides, incorporation of self-curing agents results in reducing water content in the concrete that makes the environment healthy and green. This paper mainly focusses on review of various properties of self-curing concrete by using various admixtures and the effect of using various admixtures that would help researchers to identify research gap in the area of self-curing concrete.

The Effect of Superabsorbent Polymer on Fair-Faced Concrete Performance Based on White Cement

Introducing superabsorbent polymer (SAP) into white fair-faced concrete can achieve the purpose of internal curing, which is beneficial to the popularization and application of white fair-faced concrete. The effects of the SAP mixture and internal curing water content on the properties of white fair-faced concrete were investigated macroscopically through the indexes, including slump, electric flux, standard cube compressive strength, and tensile splitting strength. The mechanism of these influence laws was further analyzed by scanning electron microscope (SEM). The results show that the slump increases with the increase of SAP content and internal curing water; the incorporation of SAP can significantly reduce the electric flux of white fair-faced concrete and improve its durability; with the increase of SAP admixture and internal curing water content, the compressive strength of white fair-faced concrete decreases, which has a significant impact on the early compressive strength; the addition of SAP is beneficial to the improvement of the tensile properties and tensile-compression ratio of white fair-faced concrete. When the SAP content is 0.2%, and the internal curing water is ten times the mass of SAP, the optimal performance of white fair-faced concrete can be achieved; the water released by the SAP promotes the secondary hydration reaction, which can refine the internal structure of white fair-faced concrete.

Effect of superabsorbent polymer and polypropylene fiber on mechanical performances of alkali-activated high-calcium fly ash mortar under ambient and elevated temperatures

This study investigated the mechanical properties of alkali-activated fly ash (AAF) mortars containing superabsorbent polymers (SAPs) and polypropylene (PP) fibers before and after exposure to elevated temperatures. AAF mortars were synthesized using sodium silicate and high-calcium fly ash as the solid activator and aluminosilicate source, respectively. This procedure classified the binder as a one-part AAF mortar. The mechanical properties of the AAF mortar, including compressive and flexural strengths, were investigated considering eight mixes with varying SAP contents (0%, 0.5%, 1%, and 2% by weight of binder) and fiber contents (0 and 0.2% by volume). Moreover, physical properties including the permeability and sorptivity were examined, and physiochemical analysis was performed to evaluate the behavior of AAF mortar at room temperature, 300, 500, and 700 °C. The results show that the compressive strength of specimens at room temperature slightly decreased owing to the increased macroporosity caused by SAPs through pre-swelling, while the flexural strength was maintained via an internal curing effect. The PP fibers significantly enhanced the flexural capacity of the cement mortar, while the compressive strength initially decreased at 28 d and later exhibited a negligible effect at 90 d. The specimens produced using SAPs were effective in preserving the residual compressive and flexural strengths compared with those without SAPs after exposure to 300 °C. Meanwhile, the residual strength of PP fiber specimens diminished after elevated temperature exposure because the melted fiber led to the excessive formation of cavities.

Effect of super-absorbent polymer on swelling pressure of compacted bentonite infiltrated by alkaline solutions

The application of bentonite in geological disposal of radioactive waste is still under evaluation, especially concerning the decreased swelling pressure of pure bentonite exposed to alkaline groundwater. In this paper, in order to improve the chemical resistance of bentonite to alkaline solutions, super-absorbent polymer (SAP), a hydrophilic polymer with much higher swelling ability than that of bentonite, was dry-blended with Gaomiaozi (GMZ) bentonite and compacted into blocks of different dry densities. Swelling pressure of the bentonite-SAP composites infiltrated with deionized water, NaOH and KOH alkaline solutions were tested, accompanied with scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP) and X-ray diffractometer (XRD) tests conducted on the selected specimens. Results showed that, for the specimens hydrated by deionized water, the swelling pressure increased with increasing SAP content, dry density and concentration of NaOH solutions. With increasing concentration of KOH solutions, however, the swelling pressure decreased obviously and tended to undergo a slow long-term degradation. Results of SEM, MIP and XRD indicate that the SAP hydrogels swell extensively to clog the inter-aggregate pores and coat the aggregates (for high density specimens) or montmorillonite stacks (for low density specimens), while do not insert into the interlayer spaces. The swelling pressure was therefore mainly contributed by the crystalline swelling of montmorillonite and the osmotic swelling of SAP. The SAP chains could be associated with the montmorillonite crystallites, protecting them from chemical attack and thus improving the chemical resistance of bentonite to alkaline solutions.

Effect of dosage of super absorbent polymer on self-consolidating concrete: Correlation between compressive strength and rheological properties

This research investigates the super absorbent polymer effect on self-consolidating concrete's compressive strength and rheological properties (SCC). The SCC mixes contained four different dosages of super absorbent polymer (SAP). The Rheological properties of SCC changed by adding SAP, and also workability decreased due to water absorption from the mix by dry SAP. The compressive strength of concrete increased, especially in air curing and gunny bag curing, at all curing ages but decreased in water curing. Experimental investigation measured the yield stress, plastic viscosity, slump flow and V-funnel time to assess the rheology of concrete and compressive strength in three curing regimes. In this study effect of super absorbent polymer on rheology and compressive strength of SCC in water curing, air curing, and gunny bag curing regimes has been revealed. Correlations have been found among Plastic viscosity, Yield stress, Slump flow value, V-funnel time, and compressive strength of concrete at 28 days of curing in three curing regimes.

Effect of Superabsorbent Polymer on the Hydration Properties of High-Performance Concrete

Effect of Superabsorbent Polymer on the Hydration Properties of High-Performance Concrete

The Effect of Superabsorbent Polymers on Mechanical Characteristics and Cracking Susceptibility of Alkali-Activated Mortars Containing Ground Granulated Blast-Furnace Slag and Copper Slag

In an attempt to increase sustainability of construction materials, both ground granulated blast-furnace slag (GGBS) and, less popular, copper slag (CS) can be used in alkali-activated composites. However, such composites are often more susceptible to cracking, triggered by the self-desiccation processes. The addition of superabsorbent polymers (SAP) may enable internal curing of concrete and prevent excessive cracking. Thus, this paper aims to evaluate the effectiveness of SAP as an internal curing agent for alkali-activated slag mortars containing GGBS and CS. The samples were activated by sodium silicate using 6.5% Na2O by mass of precursor. The evaluation was based on the analysis of mechanical properties, autogenous shrinkage, and water absorption capacity of two types of SAPs. Depending on the type of polymer, a higher alkali concentration in SAP solutions speeds up early age reactions up to 7 days. After this period, SAP collapses and reactions follow at the same pace as the reference sample. In the presence of CS, SAP with higher absorption and smaller particles well-distributed in the mix leads to a higher extension of reactions, observed in higher values of autogenous shrinkage (AS). This results in increased compressive strength of GGBS-CS mortars, achieving values 8.8% greater than the reference sample (without SAP) at 6 months. Although its leads to higher cracking susceptibility, SAP can improve mechanical properties and promote new applications for sustainable material containing copper slag.

STUDY OF A REPAIR EFFECT OF SAP-MIXED PATCH REPAIR MATERIL FOR RC MEMBER DETERIORATED BY CHLORIDE INDUCED CORROSION

The effect of Superabsorbent polymer (SAP) admixture in patch repair materials on the adhesion to the base concrete and the protection performance of reinforcing bars was investigated. In the experiment, one side of RC joint specimens were exposed to water. Water leakage from the interface between the base concrete and the repair material was reduced in the SAP specimen compared to the conventional Polymer modified mortar specimen. In addition, the half-cell potential and polarization resistance of the SAP specimens showed noble and high values, respectively, indicating the inhibition of corrosion of reinforcing bars.

Effect of Super-Absorbent Polymer (SAP) Incorporation Method on Mechanical and Shrinkage Properties of Internally Cured Concrete.

To study the effect of SAP incorporation on the early shrinkage of SAP internally cured concrete with the aim to solve the problems of early shrinkage and cracking of bridge leveling-layer concrete, using the SAP incorporation method as a parameter, the mechanical properties test of internally cured concrete, the shrinkage performance test of ring restraint and the scanning electron microscope observation test were carried out. The effects of the SAP content and incorporation method on the flowability, mechanical properties, shrinkage performance and microstructure of internally cured concrete were analyzed. The experimental results show that when the content of the SAP in concrete is 0.2% of the mass of cementitious materials, it has the least influence on the compressive strength of concrete. The addition of preabsorbed water to the SAP can delay early cement hydration, increase the later cement hydration rate and final hydration degree, and improve the concrete strength. Preabsorbed water mixed with an SAP can effectively improve the shrinkage of concrete, and the shrinkage reduction effect is more obvious than that from the dry addition of the SAP; the early cracking risk of concrete without an SAP is high, and it will crack before day 28. The addition of an SAP can strengthen the microstructure of concrete and improve its density and crack resistance, effectively avoiding concrete cracking. It is recommended that the water-absorbent resin be incorporated in a preabsorbent manner, and the SAP preabsorbent ratio is equal to the maximum water storage rate of the SAP.

Effect of super absorbent polymer and mineral additives on mechanical, shrinkage and healing properties of self-healing lightweight aggregate concrete under different curing regimes

Super absorbent polymers, which allow better moisture retention within cracks for extended periods, can be beneficial in facilitating the autogenous self-healing process of concrete incorporated with carbonate-built lightweight aggregates. In the present study, the combined effect of super absorbent polymers and mineral additives, the calcium source provider, on the self-healing properties of self-healing lightweight concrete was investigated. In addition to determining the effect on compressive strength and drying shrinkage, a destructive test by flexural strength and a non-destructive test through electrical impedance spectroscopy were conducted to evaluate self-healing efficiency under different curing regimes. The results showed that the strength was increased by adding mineral additives, while it decreased with increasing the dosage and size of super absorbent polymers. In addition, the application of super absorbent polymers has significantly improved the healing efficiency, especially by 56.1% with adding the large size of super absorbent polymers in the wet-dry cycle. Furthermore, through the analysis of electrical impedance spectroscopy, the super absorbent polymers of large particle size were proved to have excellent moisture retention within cracks in the wet-dry cycles. According to microscopic observation, the potential mechanism was proposed that the swollen super absorbent polymers were possible to further improve self-healing efficiency in the wet environment.

Effect of superabsorbent polymers on mechanical strength and cracking of mortar and concrete with water to cement ratios of 0.4 and 0.5

AbstractMost studies of adding superabsorbent polymers (SAP) into concrete focus on high‐strength concrete, while this paper aims to understand the influence of SAP on “ordinary concrete” at a w/c ratio being 0.4 or 0.5. The proposed experiments include the effect of particle size, mixing methods, and dosages on the restrained shrinkage and mechanical properties of mortar and concrete. Mortar with varying dosages of SAP (0.1, 0.2, and 0.3 wt.%) and two types of SAP (type‐a of 30–60 mesh and type‐d of 300–400 mesh) was studied to evaluate the effect of SAP on mortar's cracking and strength. Two mixing processes of SAP (dry and pre‐wetted) were used to examine the effect of SAP on the mortar's shrinkage and mechanical properties. Furthermore, concrete specimens with a w/c ratio of 0.5 were prepared to investigate the cracking performance of concrete using the restrained squared concentric ring test method, a new approach which can predict the cracks location and pattern to evaluate the restrained shrinkage of concrete. The result revealed that the addition of SAP in a prewetted state decreased the mechanical properties at early curing age. The addition of 0.3 wt.% SAP was found to have mitigated the restrained shrinkage while prolonging the time to cracking of cementitious composites. The major finding is that adding SAP to ordinary concrete reduces shrinkage and improves mechanical strength, which should be further looked into and explored in its application in engineering work.

Effect of superabsorbent polymers on microstructure and strength of blended cements mortars reinforced by polymeric fibre

Superabsorbent polymers (SAPs) efficiently reduce total shrinkage and cracking susceptibility of fibre reinforced mortars (FRM). This paper discusses the effects of SAPs on the microstructure and mechanical properties of FRM containing fly ash (FA) and ground granulated blast-furnace slag (GGBS) during a period of 180 days. Three types of cement including CEM I, CEM II/B-V and CEM III/A and three types of SAP with different chemical compositions and particle gradings were studied. The paper argues SAP's contribution to hydration of FA and GGBS and a subsequent deposition of these products on the fibres surface and in pores below 20 nm diameter. The analysis confirmed that SAPs provide additional water for hydration (internal curing) but also a required space for later hydration products (additional refilling of collapsed SAPs), resulting in more homogenous internal microstructure. This improvement is more prominent in mortars containing finer SAP (around 80 μm), which can facilitate strength recovery of up to 50%. The strength recovering process in FRM-SCM samples is boosted after the 2nd week, and is more dominant for samples containing CEM III/A.