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Phosphogypsum (PG) is an industrial solid waste which is difficult to dispose of and can cause environmental pollution. This paper investigated a low-energy-consumption preparation from PG of an environmentally friendly building material. PG was converted to α hemihydrate gypsum (α-HH) using the nonautoclaved method. Then the α-HH from PG (PGHH) was mixed with different dosages of fly ash and/or cement to obtain PGHH–fly ash–cement (PFC) cementitious materials, enhancing the water resistance of the corresponding hardened material. Results showed that the optimal mix proportion (by weight) of PGHH:fly ash:cement was 70∶24∶6 when the water resistance and mechanical strength properties of the corresponding hardened materials were comprehensively compared. With this proportion, the 3-, 28-, and 90-day softening coefficients were more than 25%, 50%, and 70% higher than those of the control group (PGHH alone). It was demonstrated that the Ca(OH)2 from hydration of cement can activate the pozzolanic reaction of fly ash, thus forming ettringite and C─ S─ H gel and making the hardened materials denser and more waterproof. The prepared PFC cementitious material has application as a building material which can provide a low-energy-consumption and environmentally friendly method for utilizing PG. [ABSTRACT FROM AUTHOR]

• Wet-grinding can effectively reduce the particle size of PS, but will lead to the gradual increase of phosphorus leaching. • Krstulovic-Dabic model can well simulate the hydration process of wet grinding phosphorous slag with paste. • The retarding effect of phosphorus decreased nucleation and crystal growth rates, thus increasing the setting time and the length of NG stage. • The utilization of wet-grinding phosphorus residue can bring significant economic and environmental benefits. In the study, the influencing factors of wet-grinding phosphorus slag (PS) and reaction kinetics on the early hydration of Portland cement were investigated. The results indicated that wet-grinding could decrease fineness efficiently while it enhanced the dissolution of phosphorus elements in PS slurry. The incorporation of PS led to lengthening the setting time for cement-based samples but the rising tendency was cut down. The Krstulovic–Dabic model could well explore the hydration process of the paste samples mixed with wet-grinding PS, but not simulate the paste incorporated with raw PS. Moreover, wet-grinding enhanced the hydration degree and rate in the nucleation and crystal growth stage, while it may shorten the duration time of the phase boundary reaction stage and decrease the hydration rate in the diffusion reaction stage. The research afforded a theoretical basis for using wet-grinding phosphorus slag as an admixture that would be eco-friendly and cost-effective. Based on the evaluation of the benefits, the wet-grinding treatment of PS and utilization of the PS slurry to replace cement could reconcile economic feasibility with environmental benefit and was an innovative approach to the reuse of PS. [ABSTRACT FROM AUTHOR]

• The particle size of CWS after wet-grinding decreased (D50 = 0.7 μm) and the pH value increased. • The C S H gel of CWS increased after wet-grinding. • The addition of CSW has significantly improved the early hydration rate of cement-based materials. Adding nano particles were supposed to displace steaming curing in manufacturing prefabricated components of concrete for avoiding thermal damage. Nevertheless, there were not yet appropriate nano particles adapted for practical production, and the main reason was those existing nano particles involved complicated technological processes and high costs. Last incompatibility with cement-based materials confined to its application. In this study, a new early strength agent was prepared by wet-grinding concrete waste slurry (CWS). The physicochemical properties of CWS after wet-grinding were analyzed by means of XRD, the particle size distribution (PSD), ICP, SEM, pH, resistivity, and TG. Finally, the effects of CWS on the early hydration processes and mechanical properties of cement-based materials were explored by means of setting time, hydration heat, chemical shrinkage, resistivity, mechanical properties, and MIP. The results showed that the particle size of CWS after wet-grinding decreased (D50 = 0.7 μm). Meanwhile, the surface area and the dissolution of alkaline ions in the solution increased, which provided nucleation sites and the alkaline environment for the early hydration of cement-based materials. Moreover, the early hydration rate of cement and mechanical properties were greatly improved. For instance, the cumulative heat release at 12 h increased by 111.7%, the induction period was shortened, the gel hole increased by 8% in 12 h, the large hole decreased by 37%, and the initial and final coagulation time was shortened by >30%, the compressive strength at 12 h increased by 406.3%, and the compressive strength was basically equivalent in the later period. The research in this paper showed that it was feasible to prepare the new early strength agent from CWS through the wet-grinding treatment, which provided a new reference for the green development of the prefabricated component industry. [ABSTRACT FROM AUTHOR]

• Absorption capacity of SAP increases with the increased stirring rate of cement pastes. • The swelling behavior of SAP is related to the PCE content. • Maximum absorptivity of SAP showed temperature and pressure sensitivity in pore solution. • SAP presented lower absorption capacity in geopolymer than the other blended cement pastes. • Maximum absorptivity of SAP decreased gradually with hydration time. Superabsorbent polymer (SAP) has water absorption and release behavior and can be used as internal curing or self-healing additive in cement-based materials. However, SAP has complicated and changeable swelling behaviors in cement-based materials, which has not been fully investigated. In present work, an AA-AM co-polymerized SAP was synthesized, and potential factors related to cement-based materials, including water-cement ratio and binder type, superplasticizer content, early hydration time, mixture stirring rate, temperature and pressure, were systemically investigated. Results indicated that maximum absorptivity of SAP decreased gradually with hydration time. SAP presented the highest absorptivity in FA and GGBS blended cement binder, and the lowest absorptivity in geopolymer, although the water-binder ratio is the same. The swelling behavior of SAP is related to the PCE content, and maximal SAP absorptivity first rises and then falls as PCE content increases. As the stirring rate increases, SAP's maximal absorptivity increases, due to the "Bernoulli's effect". In addition, the absorptivity of SAP showed temperature and pressure sensitivity, which was improved by the increased temperature or decreased external pressure. The findings in present work suggest that potential factors related to cement-based environment should be comprehensively considered for practical application of SAP in concrete engineering. [ABSTRACT FROM AUTHOR]

The aim of this paper is to evaluate the self-hydration characteristic of GGBFS activated by wet-grinding treatment (WGT). Three slag slurries with different fineness were prepared through milling with varying duration (20 min, 40 min and 60 min, abbreviated as S2, S4 and S6, respectively). The reaction kinetics, mechanical properties, hydration products and microstructure of hardened GGBFS pastes were analyzed to assess the effect of WGT on the self-hydration process of GGBFS. The results indicated that self-hydration was achieved after grinding without chemical activation and the rate of self-hydration was improved with the increased grinding duration. The setting times were dramatically shortened and the compressive strength was notably increased when prolonging the grinding time. The hydration process of GGBFS slurry after 20 min milling included incubation period, but the others did not. The electrical resistivity development of samples S2 and S4 decreased during the initial period, followed by setting, acceleration and deceleration stage. However, sample S6 exhibited an absence of the initial stage. The self-hydration products analyses indicated that the main products were calcium silicate hydrate, calcium aluminosilicate hydrate (C-A-S-H), hydrotalcite, akermanite and calcite. [ABSTRACT FROM AUTHOR]

• Ultra-fine GP with d50 of 316 nm and 5.33 μm was prepared for the first time. • Ultra-fine GP significantly improved the mechanical strength of UHPC. • Ultra-fine GP is feasible to be employed to produce low cost eco-friendly UHPC. High cost and CO 2 emissions are the issues that need to be addressed in the widespread application of UHPC. The application of mineral admixtures in UHPC has become a new development direction. Ultra-fine glass powders with median diameter d50 of 316 nm (named as nGP) and 5.33 μm (named as mGP) were fabricated to replace silica fume and blast furnace slag, respectively, to prepare eco-friendly UHPC. The outcomes of the study revealed that both nGP and mGP can significantly promote the hydration of UHPC pastes. The incorporation of ultra-fine GP increased the hydration products and improved the microstructure of UHPC due to its pore filling effect, nucleation effect and pozzolanic activity. The compressive strength of UHPC containing ultra-fine glass powders was larger than the reference ones and the optimal substitution rates of silica fume by nGP and blast furnace slag by mGP were 60% and 50%, respectively. Ultra-fine GP is feasible to be employed as multi-dimensional substitute material to produce low cost eco-friendly UHPC. [ABSTRACT FROM AUTHOR]

Highlights • FA2 with D50 = 2.67 μm obtained by wet-grinding showed high pozzolanic reactivity. • 50% FA2 replacement ratio showed higher strength than that of cement at 28 d age. • Cement-FA2 system showed great environmental and economic advantages. Abstract High volume coal fly ash (FA) cementitious system (C-FA) was reported to present great economic and environmental benefits in cement and concrete industry, but the slow strength development limited its use in real engineering practice. In this study, FA was processed by wet-grinding in order to obtain super-fine particles. Three kinds of FA, namely raw FA with D50 (Median particle size) of 19.70 μm, wet-grinded FA with D50 of 2.67 μm and 7.80 μm, were used; 30%, 50%, and 70% replacement ratio in C-FA system were designed. The compressive strength, hydration, and pore structure were investigated, and the cost and CO 2 emission of the system were also considered. The results showed that FA with D50 = 2.67 μm could be obtained by 2 hours' wet-grinding; 30% replacement ratio increased the compressive strength by 16% at 1 d age and 22% at 28 d age in comparison with the reference; surprisingly, 50% replacement ratio even showed slightly higher 28 d strength than that of the reference; the main reason for the increased strength was due to the refined the pore structure, the densified hardened system, and the promoted pozzolanic reaction of FA. The system with 30% and 50% replacement ratio of wet-grinded FA (D50 = 2.67 μm) showed greater environmental and economic advantages in comparison with cement-raw FA system. Such results would be expected to offer one new way for utilization of FA and the design of low carbon cementitious materials. [ABSTRACT FROM AUTHOR]

Highlight • TEA and TIPA noticeably hindered the formation of C-(A)S-H gel at 7 d age. • TEA accelerated the formation of hydrotalcite-like phase at 7 d age. • TEA and TIPA could expedite the dissolution of ferric phase in WGGBS. • 28 d strength of 10.0% cement-90.0% WGGBS-0.05%TEA reached 43.7 MPa. Abstract In this study, a commercially available ground granulated blast-furnace slag (GGBS) was further processed by wet grinding, and WGGBS (wet-grinded GGBS) slurry with superfine particles was obtained. To avoid self-hydration of slag and augment the grinding efficiency, one commercially available polycarboxylate superplasticizer was added. The binder, composed of 10.0% cement and 90.0% WGGBS with the addition of 0.05% triethanolamine (TEA) and 0.05% triisopropanolamine (TIPA), was designed; the cement was added to provide alkali environment and calcium ions, and organic alkali was used to promote the dissolution of GGBS. The compressive strength of mortar and hydration mechanism was investigated. The results showed that wet grinding exhibited high grinding efficiency; D(50) value of particle size distribution of WGGBS was reduced from 18 μm to 2.10 μm by wet grinding for one hour. Compressive strength of hardened WGGBS mortar was 20 MPa and 28 MPa at 7 d and 28 d, and 10% cement replacement ratio of the WGGBS increased the strength to 24.6 MP at 7 d and 32.2 MPa at 28 d. Furthermore, in C-WGGBS, 0.05% TEA increased the 7 d strength by 23%, with the value of 30.27 MPa, but 0.05%TIPA slightly reduced it to 23.5 MPa, with a decrease by 5%. Mechanism behind the increase was due to the accelerated formation of hydrotalcite-like phase, despite the retarding effect on formation of C-(A)S-H gel; the slight decline by TIPA was mainly because of the retarding effect of formation of C-(A)S-H gel as well as its air-entraining effect. Moreover, both TEA and TIPA increased the 28 d strength of cement-WGGBS system, because TEA and TIPA were able to facilitate ferric and aluminum dissolution and expedite the formation of C-(A)S-H gel as well as hydrotalcite-like phase. Additionally, it was worth noting that 0.05% TEA could make 28 d strength of the binder, composed of only 10% cement, reach 43.7 MPa, in accordance with the requirement of 42.5 grade cement. [ABSTRACT FROM AUTHOR]

Abstract In this study, the super-fine ground granulated blast furnace slag was obtained by wet grinding (i.e. WGBBS), and an attempt to activate the super-fine ground granulated blast furnace slag by sodium sulfate (SS) and sodium carbonate (SC) was made. SS/SC-activated WGGBS samples were prepared and cured at the room temperature. The compressive strength at the age of 3 d, 7 d, 28 d, and 56 d was tested. Hydration heat was assessed, and micro structure and hydrates were also characterized with XRD, TG-DTG, SEM-EDS, and NMR; the pore structure was assessed with MIP. The results showed that SS and SC efficiently activated the hydration of WGGBS with D50 = 3.87 μm at the room temperature, and such high activating efficiency of SS and SC under room temperature was seldom reported in the literature. The mechanism behind was mainly because of the super-fine particles of slag with greater amounts of hydration points, which were produced in the process of wet grinding. Difference in activating efficiency between SS and SC was mainly because the anionic groups acted as different roles in hydration process: SS could induce the formation of ettringite while SC could induce the formation of calcite. Such results were expected to provide guidance on designing weak base-activated slag system. [ABSTRACT FROM AUTHOR]

Abstract Lithium slag is a by-product of lithium carbonate industry; in the past decades, due to ascending demand of lithium salts, emission of this kind of solid waste is dramatically increased and results in serious environmental problem. Utilization of lithium slag is of great importance to the sustainable development of lithium carbonate industry. In this study, one new way to utilize lithium slag in sulphoaluminate cement system was attempted. Lithium slag was processed with wet grinding, in order to obtain fine particles and facilitate the ions dissolution. Addition of wet-grinded lithium slag was expected to improve the early strength of sulphoaluminate cement. The hydration mechanism was investigated in terms of setting time, hydration process, hydrates, and pore structure. The results show that lithium slag with D(0.5) of 3.04 μm, which is extremely difficult to be prepared in dry-grinding system, can be easily obtained with wet-grinding process; the ions dissolution of lithium, aluminum, and silicon phase can also be significantly facilitated in wet-grinding process. With the dosage less than 10%, wet-grinded lithium slag can notably promote the early strength of the sulphoaluminate cement paste, and the main reason for the promotion is not only because of the filling effect of fine particles and nucleation seed induction of nano particles formed in wet-grinding process, but also due to the fact that the dissolved lithium can noticeably facilitate the precipitation of hydrates to induce the cement hydration. The findings suggest that lithium slag has great potential to be utilized in sulphoaluminate cement system, and also provide one new way to utilize solid waste in cement-based materials. Highlights • LS with D(0.5) of 3.04 μm can be easily obtained with wet-grinding process. • Wet-grinding process can facilitate the dissolution of ions of LS. • Wet-grinded LS can enhance the early hydration of SAC. • LS can be utilized in SAC system as accelerator by wet grinding process. [ABSTRACT FROM AUTHOR]

This research aims to explore the feasibility of using low-activity high alumina ferronickel slag (FS), carbide slag and hemihydrate phosphogypsum (HG) as main ingredients to fabricate supersulfated cement (SSC). The effect of HG dosage and FS fineness on hydration and compressive strength of SSC-FS was systematically investigated. Experimental results indicated that high mechanical strength can be achieved at ambient temperature by adjusting HG dosage and FS fineness. Increase in HG dosage postpones the initial formation of hydrates to some extent, but the amount of the final hydration products is promoted to generate higher mechanical strength. FS with smaller particle size has higher reaction activity that significantly accelerates the hydration process of SSC, leading to higher compressive strength and smaller volume expansion of SSC, and more ettringite crystals with smallish morphology formed in the pastes. If the particle size of FS is too small, however, ettringite crystals tend to precipitate at the surface of FS particles, which is unfavorable for the development of microstructure and will restrict the generation of C–S–H, thus resulting in a decrease in compressive strength and an increase in volume expansion. [ABSTRACT FROM AUTHOR]

In this study, two different ultra-fine ground granulated blast furnace slag referred to as GS (i.e., by dry-winnowing method) and WS (i.e., by wet-grinding method) were obtained, and the hydration and rheology of activated ultra-fine ground granulated blast furnace slag (activated-BFS) with carbide slag and anhydrous phosphogypsum (AG) as combined activator were systematically investigated by means of setting time, workability, rheological behavior, compressive strength, autogenous shrinkage, electrical resistivity, SEM, XRD and TG-DTG. The results showed that the limiting factor is the BFS type, and not the AG dosage in terms of setting time, and their rheological behavior fitted with H–B model. WS and increase in AG dosage significantly reduced the plastic viscosity, shear stress and yield stress of activated-BFS pastes. The WS presented higher initial reaction activity that generated more hydrates in the early age, restricting the further hydration of BFS particles especially when AG dosage exceeded 10%, thus leading to the different compressive strength development trends between mixtures containing WS (WS/A) and GS (GS/A). The compressive strength of GS/A mixtures increased with increasing AG dosage and reached 39.9 MPa at 3 days, while WS/A first increased and then decreased. The activated-BFS with carbide slag and AG is technically feasible to be employed as cementitious materials in the production of concrete. [ABSTRACT FROM AUTHOR]

• Wet grinding could be used to improve the hydration activity of GGBFS-SS binary precursor activated by sodium sulfate. • SS used as partial-substitution precursor of GGBFS decreased the setting time and improve the early strength. • Excessive SS induced micro-cracks and strength decrease in later age. • The optimum content of WSS-GS paste was 15%SS-85%GGBFS activated by sodium sulfate. Weak base Alkali-activated materials (AAM) is a potential approach to further reduce energy consumption and eco-friendly. Long setting time and low early strength limit the application in engineering. In this study, steel slag (SS) was used as a partial-substitution precursor of ground granulated blast furnace slag (GGBFS), and wet-grinded SS-GGBFS (WSS-GS) binary binders activated by sodium sulfate were designed. The results showed that the alkalinity of WSS-GS slurry was improved by the addition of SS, and the early hydration reaction and strength were promoted greatly. However, excessive SS was harmful to strength development at later age for quantity reduction of hydration products and microstructure deterioration. 15%SS-85%GGBFS activated by 3% Na 2 O-E sodium sulfate was verified with a desired performance, initial setting time was shortened by 60% and 1 d compressive strength was increased by 91% compared to GGBFS. These results provide guidance on designing of weak base-activated slag system and utilization of mass SS. [ABSTRACT FROM AUTHOR]

• Nano cement particle can be prepared in mechanical method of wet grinding. • Nano cement particles act as nucleation seed to significantly improved cement hydration and refine the pore structure. • The 12-h strength of mortars matrix can be effectively enhanced and without compromising the 28-d compressive strength. In this study, nano cement particles (Nano-C) were prepared via wet grinding cement. Nano-C was characterized by laser particle size distribution, X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Scanning electron microscope (SEM), Transmission electron microscope (TEM) and 29Si magic-angle spinning nuclear magnetic resonance (29Si MAS NMR). The particle size of Nano-C was D50 = 53.1 nm. In order to disperse the nano particles, polycarboxylate superplasticizer was used in the process of grinding. The results show that 0.5%, 1.0%, 2.0%, and 4.0% Nano-C could increase the 12-h compressive strength by 49%, 109%, 194% and 197%, in comparison with the reference. The influence of Nano-C on the hydration, hydration products, microstructure was tested by means of hydration heat, chemical shrinkage, XRD, Thermogravimetric analysis (TGA), SEM, 29Si MAS NMR, and Mercury injection porosimetry (MIP). The results revealed that Nano-C not only used as distinguished nucleus seed to enhance the PC system hydration but also exhibited high hydration activity to produce C-S-H gel to further raise the PC hydration up. These findings provided a novel way to prepare nanomaterials, which was expected to provide a way to improve the early strength of precast concrete. [ABSTRACT FROM AUTHOR]

• Wet-grinded CS slurry with D50 of 3.0 μm was used as a lime source. • Setting times and hydration heat release were clearly promoted by the ultrafine WCS. • Both the early and late age strength was notably enhanced by appropriate WCS addition. • Carbonation resistance of high volume WFA blended composites was notably improved by WCS. Fly ash (FA) with high glassy phase content is a pozzolanic material with low activity, while carbide slag is a solid waste with portlandite crystals embedded in the impurity phases. Herein, wet-grinding method was used twice to improve the pozzolanic reactivity of FA and promote the dissolution of embedded calcium hydroxide in the CS as a lime source, respectively. Wet-grinded FA slurry (WFA) with D50 of 2.5 μm and wet-grinded CS slurry (WCS) with D50 of 3.0 μm were prepared. It was found that setting times, hydration heat release, early and late compressive strength, carbonation resistance of high volume WFA blended composites were significantly enhanced by WCS, attributed to the pre-dissolved calcium resource and alkali reserve. However, an excessive amount (12 wt%) of WCS addition causes an abnormal decrease in strength, due to the microstructure degradation by coarse portlandite crystals. Higher proportion of C-S-H might be ready for carbonation in high volume WFA blended composites, due to the promoted Al incorporation in C-S-H by wet-grinding. [ABSTRACT FROM AUTHOR]

• Wet grinding could refine waste concrete recycled powder (RP) to submicron particles. • 2~6% submicron RP enhanced the early hydration of plain PC and GBFS/FA-PC systems. • This paper was expected to develop a novel approach for the utilization of RP. Utilization of waste concrete recycled powder (RP) in cementitious materials faced enormous challenge, because of low activity and huge water demand. In this paper, RP was treated by wet grinding to prepare submicron-RP (SRP), and then SRP was used as an accelerator in various cementitious systems, including Portland cement system (PC), PC-granulated blast furnace slag (PC-GBFS), and PC-fly ash (PC-FA) system. The compressive strength, hydration heat, hydration products, and microstructure of these systems were studied. Results showed that SRP with an average diameter of 594 nm was obtained by wet grinding. In PC paste, at the age of 12 h, 6% SRP could augment the compressive strength by 150% and hydration heat by 100%, in comparison with the paste without SRP; in PC-GGBS or PC-FA system, the similar results were also found. The reason was because of the excellent nucleation effect to significantly facilitate the hydration of PC and promote the formation of hydrates; moreover, due to the filling effect of SRP, the microstructure of hardened pastes was refined. The research could provide a novel approach for the utilization of RP in precast engineering. [ABSTRACT FROM AUTHOR]

• Phosphate ester groups were introduced as side chain to modify PCE. • Performance of modified PCE in gypsum paste was investigated. • Stronger adsorption capacity of phosphate ester contributed to the dispersibility. • Crystal precipitation of calcium sulfate dihydrate was inhibited by PCE. In this study, 2-hydroxylethyl methacrylate phosphate was introduced as side chain to modify polycarboxylate superplasticizers (PCEs), and its performance in gypsum paste was systematically investigated. The results show that the introduction of phosphate ester can increase the water reduction ratio from 24% to 58%, and also extend the final setting time, showing excellent dispersing ability and retarding effect. The excellent dispersion was due to the stronger adsorption capacity of phosphate ester leading to high adsorption amount and high absolute value of zeta potential. In addition, the negative effect of the high adsorption amount on the crystal precipitation of calcium sulfate dihydrate is considered to be an important reason for retarding effect. [ABSTRACT FROM AUTHOR]

• The nano-LS of D50 = 300 nm was prepared by wet griding. • Nano-LS could accelerate the hydration of SAC. • Providing a new way to utilize LS in SAC system. As a by-products of lithium carbonate industry, emission of lithium slag (LS) was increasingly increased due to the huge market demand of lithium salt. Therefore, LS disposal faces great challenge. In the study, a new approach to use LS in sulphoaluminate cement (SAC) system to improve the early compressive strength was proposed. Nano-lithium slag (nano-LS) was prepared via wet grinding, and the effect of nano-LS on hydration mechanism of SAC was investigated. The results indicated that nano-LS with D50 of 300 nm was prepared. In comparison with the Blank, 4.0% nano-LS promoted the 7 h compressive strength from 4.5 MPa to 24.3 MPa, with an increase by more than 4 times, and an increase by 28% at 1 d age; it also reduced the initial and final setting time to 16 min and 23 min, being reduced by 33.3% and 37.5%. This phenomenon was because nano-LS accelerated the hydration of SAC, and 4.0% dosage even made the inducing period disappear. The reason for the accelerated hydration was that the nano particles in nano-LS slurry acted as excellent nucleation seeds for speeding of the formation of hydration products. Additionally, the promoted dissolution of lithium salt during the process of wet milling also facilitated precipitation of aluminum phase to accelerate the SAC hydration. Consequently, nano-LS was expected as an excellent accelerator in SAC system. All of findings suggested an innovation new way to utilize LS in SAC system. [ABSTRACT FROM AUTHOR]

• Long wet-grinding duration can modify the morphology of WGP particles. • WGP dramatically improved the workability of fresh pastes regardless of the fineness. • The WGP (D50 in the range of 0.9–10.5 μm) could accelerate the reaction of cement. • The setting time could be shortened when the median grain size reduced to 5 μm. This work aims at evaluating the influence of wet-grinded superfine waste glass powder (WGP) as a supplementary material in cement based materials. WGP with different fineness was evaluated and incorporated into cement with a proportion of 20%. The results showed the WGP particle had regular shape when the wet grinding duration reached 60 min. WGP dramatically improved the workability of fresh pastes regardless of the fineness. The setting time of WGP incorporated pastes was shortened if the median grain size was reduced to 5 μm. The WGP could accelerate the reaction of cement, higher chemical shrinkage and larger electrical resistivity. [ABSTRACT FROM AUTHOR]

• D50 of raw materials decreased to around 3 μm by wet grinding. • Strength of WGGBS increased clearly by the use of wet grinded waste gypsum. • Increased strength was attributed to the evolution of hydrates and porosity. Replacement of Portland cement by industrial wastes has been accepted as a potential way to reduce carbon emissions. Ground granulated blast furnace slag (GGBS), desulphurization gypsum (DG), and phosphogypsum (PG), known as the common industrial wastes, were used in this study. Binders comprised of GGBS and waste gypsum were designed to develop a novel low carbon material; in order to promote the reactivity raw materials were processed by wet grinding. Compressive strength was examined and hydration process was researched by XRD, TG, NMR, SEM, and MIP. Results showed that wet grinded PG (WGPG) and wet grinded DG (WGDG) were able to greatly augment compressive strength of wet grinded GGBS (WGS) system. The reasons were attributed to the accelerated formation of ettringite and the reduced porosity. On the one hand, the presence of ettringite could construct the crystal skeleton resulted in the hardening of system accelerated. On the other hand, the constantly produced C-S-H gel densified the microstructure and decreased the porosity significantly. Moreover, in comparison with WGDG-WGS system, the early strength of WGPG-WGS system was lower caused by the retardation effect of phosphorus in PG. Results was expected to be used for the design of low carbon materials. [ABSTRACT FROM AUTHOR]