Magnesium Phosphate Cement Paste Research Articles

Hydration properties of magnesium phosphate cement paste mixed with metakaolin and silica fume

AbstractMagnesium phosphate cement (MPC) exhibits a faster setting time and higher early strength, making it suitable for crack repair. However, its application in civil engineering is hindered by its fast initial hydration rate and poor water resistance. To address these limitations, metakaolin (MK) and silica fume (SF) were utilized to enhance the properties of MPC. The effects of MK and SF on the setting time, compressive strength, water resistance, hydration process, and microstructure of MPC were investigated. The results demonstrate that both MK and SF significantly prolong the setting time of MPC and improve its water resistance. The main hydration products of MPC, after incorporating MK and SF, are k‐struvite (MgKPO4·6H2O) and unreacted MgO. The presence of MgSiO3 and AlPO4 also contributes to the enhancement of compressive strength and water resistance. The incorporation of MK and SF actively participates in the hydration reaction of the MPC system. Furthermore, MgSiO3 and AlPO4 intertwine with MKP, resulting in a denser internal structure of the cured MPC, thereby improving its water resistance.

Preparation and properties of gradient fire & corrosion protection magnesium phosphate cement coatings

Fire and corrosion protection are the main problems limiting the application of steel. Gradient fire & corrosion protection coating for steel structures was prepared by magnesium phosphate cement (MPC) with high bond strength, excellent anti-corrosion, and high-temperature resistance. The interface inside the MPC coating and of the MPC coating and steel plate were observed. The bonding strength, corrosion, and fire performance of MPC coating were investigated before and after dry-wet cycles. The results showed MPC had high bond strength with itself even under dry-wet cycle conditions. Only 6 mm MPC coating can meet the fire and corrosion resistance of steel structures. When the total thickness of MPC coating was 6 mm, the rising thickness (0–1.6 mm) of MPC paste improved the bond strength to 2.5 times and anticorrosive performance but reduced the fireproof performance of MPC coating. Even though the thickness of the MPC paste was 1.6 mm, the fireproof performance of MPC coating remained abundant. After 28 dry-wet cycles, the fireproof performance of MPC coating with 0.4 mm MPC paste was comparable to that before the dry-wet cycle. The bond strength was still more than 0.3 MPa, which can still meet the requirements of the specification.

Efficiency and Mechanism of Surface Reinforcement for Recycled Coarse Aggregates via Magnesium Phosphate Cement.

Recycled aggregate concrete (RAC) exhibits inferior mechanical and durability properties owing to the deterioration of the recycled coarse aggregate (RCA) surface quality. To improve the surface properties of RCA, the reinforcement efficiency of RAC, and the maneuverability of the surface treatment method, this study used magnesium phosphate cement (MPC), a clinker-free low-carbon cement with excellent bonding properties, to precoat RCA under three-day pre-conditioning. Moreover, variable amounts of fly ash (FA) or granulated blast furnace slag (GBFS) were utilized to partly substitute MPC to enhance the compressive strength and chloride ion penetration resistance. Subsequently, FA-MPC and GBFS-MPC hybrid slurries with the best comprehensive performance were selected to coat the RCA for optimal reinforcement. The crushing value and water absorption of RCA, as well as the mechanical strengths and durability of RAC, were investigated, and microstructures around interfaces were studied via BSE-EDS and microhardness analysis to reveal the strengthening mechanism. The results indicated that the comprehensive property of strengthening paste was enhanced significantly through substituting MPC with 10% FA or GBFS. Surface coating resulted in a maximum reduction of 8.15% in the crushing value, while the water absorption barely changed. In addition, modified RAC outperformed untreated RAC regarding compressive strength, splitting tensile strength, and chloride ion penetration resistance with maximum optimization efficiencies of 31.58%, 49.75%, and 43.11%, respectively. It was also evidenced that the improved MPC paste properties enhanced the performance of modified RAC. Microanalysis revealed that MPC pastes exhibited an excellent bond with RCA or new mortar, and the newly formed interfacial transition zone between MPC and the fresh mortar exhibited a dense microstructure and outstanding micro-mechanical properties supported with an increase in the average microhardness value of 30.2-33.4%. Therefore, MPC pastes incorporating an appropriate mineral admixture have enormous potential to be utilized as effective RCA surface treatment materials and improve the operability of RCA application in practice.

Comparative study on the effect of bauxite tailings on properties of magnesium-phosphate-cement-based materials before and after calcination

To study the recycling of bauxite tailings (BT) and the poor water resistance of magnesium phosphate cement (MPC), the effects of BT and calcined BT (CBT) on the setting time, fluidity, drying shrinkage properties, compressive strength, and water resistance of MPC were investigated. The results showed that BT and CBT regulated the setting time and fluidity of MPC, adjusted the pH of the MPC paste, and decreased the generation rate of hydration products. The incorporation of BT decreased the early strength and increased the late strength of MPC, while the incorporation of CBT increased the MPC strength during the 28 d duration. Further, the optimal incorporation amount of BT and CBT was found to be 15 wt%. Although the water resistance of MPC was improved by blending BT or CBT, the effect of CBT was more significant, with a 32% reduction in compressive strength loss in the CBT groups compared to the control group for 28 d of curing. The alumina in BT was calcined and activated such that AlPO4 produced by secondary hydration reaction with phosphate enhanced the bonding of the solids and filled the pores and cracks of the MPC specimens, thereby increasing the densities of the specimens and improving their water resistance.

Effects of the combination of NH4H2PO4 and KH2PO4 on the interfacial bond between magnesium phosphate cement and steel fiber

In this paper, a double-side pullout testing method was used to characterize the bond strength and pullout energy of steel fiber in magnesium phosphate cement (MPC). The effects of phosphates on flowability, setting time, hydration heat, and phase composition of MPC were evaluated as well. The results indicate that ammonium dihydrogen phosphate (ADP) and potassium dihydrogen phosphate (PDP) show significant effects on the bond properties between MPC and steel fiber. Magnesium ammonium phosphate cement (MAPC) can generate ammonia during hydration, which is easy to form pores and voids in the interfacial zone. However, the calculated total volume shrinkage produced by the hydration of MAPC is greater than that of magnesium potassium phosphate cement (MPPC), which is conducive to greater friction at the interface. There is no gas generated during the hydration of MPPC, but the elastic modulus of K-struvite is lower than that of struvite. The combined use of ADP and PDP is conducive to reducing the porosity and increasing the hardness of the interface zone and improving the bond properties of MPC and steel fibers. The hydration products of MPC paste around the steel fiber form a highly compact interfacial zone with few defects, leading to mechanical interlock and strong friction. Moreover, the etching of the surface of mild steel fiber in MPC and penetration of soluble phosphates promote the interfacial bonds.

Study on solidification mechanism of magnesium phosphate cement on heavy metals Cu2+

Magnesium phosphate cement (MPC) can be used in the fields of solidification of heavy metal ions in hazardous waste. Scholars at home and abroad had done a lot of research on the solidifying efficiency, mechanical properties and solidifying mechanism of MPC solidifying copper ion. However, it is difficult to analyze and study the early hydration of MPC due to its rapid condensation. In view of the problems in current research, MPC suspension and paste were selected to systematically study the pH value, conductivity, ion concentration, hydration heat release, leaching toxicity, mechanical properties of MPC solidifying Cu2+. The product evolution process of MPC solidifying Cu2+ and the occurrence mode of Cu2+ in MPC were studied. The results showed that Cu2+ delayed the hydration reaction of MPC, the total amount of hydration heat in MPC suspension decreased and the total amount of hydration heat in MPC paste increased gradually in the later stage. The products of MPC suspension solidifying Cu2+ included Mg0.95Cu0.05O, Mg0.90Cu0.10O and Cu4(PO4)2O. The products of MPC paste solidifying Cu2+ included Mg0.95Cu0.05O and solid solution Mg0.45Cu0.55KPO4·6 H2O. The properties of the products were stable. The solidifying methods of MPC to Cu2+ included adsorption, physical coating, ion exchange, chemical bonding and many ways of synergy. The efficient solidification of Cu2+ by MPC conformed to the concept of environmental sustainable development.

Experimental magnesium phosphate cement paste increases torque of trochanteric fixation nail advanced™ blades in human femoral heads

BackgroundThe use of polymethylmethacrylate cement for in-situ implant augmentation has considerable disadvantages: it is potentially cytotoxic, exothermic and non-degradable. Therefore, the primary aim of this study was to develop a magnesium phosphate cement which meets the requirements for in-situ implant augmentation as an alternative. Secondly, this experimental cement was compared to commercial bone cements in a biomechanical test set-up using augmented femoral head blades. MethodsA total of 40 human femoral heads were obtained from patients who underwent total hip arthroplasty. After bone mineral density was quantified, specimens were assigned to four treatment groups. A blade of the Trochanteric Fixation Nail Advanced™ was inserted into each specimen and augmented with either Traumacem™ V+, Paste-CPC, the experimental magnesium phosphate cement or no cement. A rotational load-to-failure-test (0° to 90°) was performed. FindingsA conventional two-component magnesium phosphate cement failed in-situ implant augmentation consistently due to filter pressing. Only a glycerol-based magnesium phosphate paste was suitable for the augmentation of femoral head blades. While the blades augmented with Traumacem™ V+ yielded the highest maximum torque overall (22.1 Nm), the blades augmented with Paste-CPC and the magnesium phosphate paste also showed higher maximum torque values (15.8 and 12.8 Nm) than the control group (10.8 Nm). InterpretationThis study shows for the first time the development of a degradable magnesium phosphate cement paste which fulfills the requirements for in-situ implant augmentation. Simultaneously, a 48% increase in stability is demonstrated for a scenario where implant anchorage is difficult in osteoporotic bone.

Behavior of magnesium phosphate cement with addition of sulphoaluminate cement at elevated temperatures

Magnesium phosphate cement (MPC) as repair materials of the structures or package materials for wastes may be exposed to elevated temperatures during fire attack. When MPC paste was exposed to about 1300 °C, a sharp increase in compressive strength was observed due to sintering. However, MPC exposed to elevated temperature, especially below 1000 °C showed a sharp decrease in compressive strength. Ye'elimite mineral in sulphoaluminate cement (CSA) has been proven to take part in the hydration of MPC and form some amorphous phases. The introduction of CSA in MPC could provide reactive Al and Si, which may be beneficial to improving the high temperature resistance of MPC. The present study aims to introduce CSA into MPC to improve its thermal properties at elevated temperatures. MPC pastes with pure dead burned MgO and various contents of CSA were prepared and exposed at elevated temperatures from 200 to 1100 °C. The compressive strengths, strength retention, dimensional changes, weight loss, phase changes, microstructures and open porosities of MPC pastes with CSA at elevated temperatures were studied. The proper addition of CSA in MPC pastes could form some new amorphous phases, reduce the open porosities, promote the sintering progress and enhance the strengths at elevated temperatures. To promote the properties of the MPC pastes at elevated temperatures, 10% and 30% CSA were recommended to replace dead burned MgO in MPC pastes at exposure temperatures above 1000 °C and below 400 °C, respectively.

Preparation and properties of hydrotalcite-foamed magnesium phosphate cement for fire protection of steel structures

Foamed magnesium phosphate cement (MPC) is prepared for the fire protection of steel structures based on the carbonate decomposition reaction of hydrotalcite in acidic MPC paste. Hydrotalcite decomposes in an acidic MPC slurry to generate CO2, and approximately 50% of the theoretical gas generation remains in the MPC slurry to form foamed MPC with an apparent density of < 650 kg/m3 and 1-d compressive strength of > 4.0 MPa. The actual gas production of hydrotalcite in the MPC slurry gradually increases as the hydrotalcite content increases and the M/P ratio decreases. The fine hydrotalcite particles refine the pores and obstruct the paths between them, resulting in closed and uniform pores. When the thickness of the foamed MPC coating on the steel plate surface is only 6.0 mm, the temperature on the steel plate back after being subjected a 60 min fire resistance test is about 400 °C, which is significantly lower than the critical temperature (538 °C) for the steel structure to remain stable after encountering fire. Foamed MPC exhibits excellent fireproofing performance owing to its high porosity, low thermal conductivity, the release of CO2 in the pores, and the dehydration of hydration products, which retards heat transfer in case of fire.

Ready-To-Use and Rapidly Biodegradable Magnesium Phosphate Bone Cement: In Vivo Evaluation in Sheep.

In clinical practice, hydroxyapatite (HA) cements for bone defect treatment are frequently prepared by mixing a powder component and a liquid component shortly before implantation in the operation theater, which is time-consuming and error-prone. In addition, HA cements are only slightly resorbed, that is, cement residues can still be found in the bone years after implantation. Here, these challenges are addressed by a prefabricated magnesium phosphate cement paste based on glycerol, which is ready-to-use and can be directly applied during surgery. By using a trimodal particle size distribution (PSD), the paste is readily injectable and exhibits a compressive strength of 9-14MPa after setting. Struvite (MgNH4 PO4 ·6H2 O), dittmarite (MgNH4 PO4 ·H2 O), farringtonite (Mg3 (PO4 )2 ), and newberyite (MgHPO4 ·3H2 O) are the mineral phases present in the set cement. The paste developed here features a promising degradation of 37% after fourmonths in an ovine implantation model, with 25% of the implant area being newly formed bone. It is concluded that the novel prefabricated paste improves application during surgery, has a suitable degradation rate, and supports bone regeneration.

Water-Immersion Stability of Self-Compacting Potassium Magnesium Phosphate Cement Paste

For the repair of narrow cracks in concrete, the potassium magnesium phosphate cement (MKPC)-based material paste should have high fluidity and self-compacting ability, making it convenient for pouring and compacting. A self-compacting MKPC paste that meets the index requirements recommended by the European Federation of National Associations Representing for Concrete (EFNAFC) was prepared by increasing the water-cement ratio and adding water glass and fly ash (FA). Specimens of self-compacting MKPC paste were subjected to long-term water corrosion tests, which found that those high-fluidity MKPC paste specimens (reference sample M0) that were produced with only an increased water-cement ratio lost 15-30% of their strength. The residual ratio of folding to compression was 84.6%, and the volume expansion rate was 7.78 × 10-4 after immersion in water for 560 days. The strength residual rate of MKPC slurry (M1) modified by sodium silicate and fly ash is over 90% after 560 days of immersion in water, and the residual rate of flexural-compressive ratio is 101.3%, which meets the requirements of hydraulic cement-based materials. The volume expansion rate of M1 is 5.19 × 10-4, which is 67% of the reference sample M0 with the same water immersion age.

Effect of fly ash on the rheological properties of potassium magnesium phosphate cement paste

To ensure that the potassium magnesium phosphate cement (MKPC) paste is both easily pourable and compact when repairing narrow cracks, the paste must be capable of self-compacting. Herein, the effects of fly ash (FA) on the workability, rheological properties, and early strength of the MKPC paste were tested, and the physical phase composition and microstructure of the paste were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results suggested that the working properties of the resulting MKPC paste satisfy the index requirements of the European Design Code for Self-Compacting Concrete of European Federation of National Associations Representing for Concrete when 10 % and 20 % FA are used instead of magnesium oxide powder. The early plastic viscosity of the slurry mixed with 10 % and 20 % (M1, M2) increased by 0.114 and 0.174 Pa s, respectively, in relation to that of the MKPC paste without FA (M0). This result indicated that the FA admixture increases the plastic viscosity of the MKPC paste because FA can promote the early hydration of the MKPC paste and consume more free water. The static yield stress of M2 pastes blended with 20 % FA and the thixotropic ring area decreased by 31.89 Pa and 971.12 Pa s−1, respectively, in relation to those of M0. The addition of an appropriate amount of FA reduces the early static yield stress and improves the thixotropy of the MKPC pastes owing to the dispersing effect of spherical particles in FA and the tumbling effect. Owing to heterogeneous core-forming, active, and microaggregate effects of FA, the structure of the hydrated 1 d M2 sample was significantly denser than that of M0, which subsequently improved the 1 d strength of the hardened body.

Effect of magnesium-to-phosphate ratio on the corrosion resistance of magnesium alloy embedded in magnesium potassium phosphate cement

Effect of magnesium-to-phosphate (M/P) ratio on the corrosion resistance of magnesium alloys embedded in magnesium phosphate cement pastes was studied via electrochemical methods and surface characterizations in this study. Results show that corrosion resistance of magnesium alloy increased with the increased M/P ratio. pH played a dominant role in protective capability of oxide film formed on magnesium alloy. M/Ps 7 and 12 leads to formation of oxide film mainly consisting of magnesium phosphates. In contrast, an oxide film composed of magnesium and aluminium oxide/hydroxide formed in M/P 17, possibly with adsorption of phosphate ions which further enhances the corrosion resistance.

Study on graphene oxide reinforced magnesium phosphate cement composites

Graphene oxide (GO) is an excellent nano reinforcing material. This paper presents the effect of GO addition on the hydration, microstructure and mechanical properties of magnesium phosphate cement (MPC). MPC with GO contents of 0.00, 0.02, 0.04, 0.06, 0.08 and 0.10 % was prepared. The functional groups, mechanical properties, phase composition and reinforcement mechanism of the GO-MPC composites were tested and analysed. The results showed that water adhered to the GO, which led to a decrease in the fluidity of the MPC paste. With increasing GO content, the most probable pore size of MPC first decreased and then increased. By adding 0.04 % GO, the most probable aperture of MPC was reduced from 11.3 μm to 0.9 μm. The proper addition of GO could refine the pore size, densify the microstructure and improve the mechanical properties of MPC. An appropriate dosage of GO promoted the hydration of MPC, resulting in more hydration products, including potassium magnesium phosphate hexahydrate (MKP), better growth of MKP with higher crystallinity.

Investigation and Optimisation of the Rheological Properties of Magnesium Potassium Phosphate Cement with Response Surface Methodology

Magnesium phosphate cement (MPC) is a promising alternative cement. However, the rheological property of this new binder is still to be explored. In this study, Response Surface Methodology (RSM) was adopted with Central Composite Design (CCD) to establish mathematical models describing the rheological characteristics of MPC in terms of initial mini slump (Y1), mini-slump loss (Y2), yield stress (Y3) and plastic viscosity (Y4), as a function of three independent variables, namely, water-to-solid ratio (W/S ratio, X1), MgO to MKP ratio (M/P ratio, X2) and borax dosage (X3). The results show that the M/P ratio and borax dosage could significantly affect the yield stress and mini-slump loss of MPC, while the W/S ratio was the significant coefficient influencing plastic viscosity and initial mini slump. The numerical optimised values of X1, X2 and X3 were 0.280, 7.528 and 0.170, respectively, and an MPC paste with desirable rheological characteristics (Y1 161.858 mm, Y2 11.282, Y3 0.680 Pa, Y4 0.263 Pa·s) with the highest desirability of 0.867 can be obtained.

Early-age mechanical properties and hydration degrees of magnesium phosphate cement paste in freezing winter of cold regions

Magnesium phosphate cement (MPC) paste is a good patching material for concrete repair works. This study focused on early-age mechanical properties and hydration degrees of MPC paste in freezing winter of two types of cold regions, which are highland regions and high-latitude regions. MPC pastes with different mix proportions under different curing modes were experienced a series of experiments, including fluidity and setting time, compressive strength, pore structure characterization, thermogravimetric analysis, X-ray diffraction and electron microscopic scanning. Results showed that for winter applications, MPC pastes in simulated highland temperature conditions performed better than those in true high-latitude temperature conditions, illustrated by pore structure analyses and hydration products analyses. The best M/P ratios for highland applications and high-latitude applications were respectively 4 and 5, which respectively delivered 24 h strengths at about 50 MPa and 25 MPa. Even in severe cold winter, the setting of MPC paste depended on the hydration speed instead of the frozen action. Mixing water temperature was good for early-age hydration of MPC paste which cured for six hours in natural cold environment, however, the effect vanished at 24 h. Both the amounts of struvite and unhydrated phosphate, which could be quantitatively assessed by TG-DSC tests or qualitatively assessed by XRD test, were good indicators of the hydration degree of MPC paste in cold weather. These results provided valuable suggestions for winter applications of MPC paste in different types of cold regions.

Fractal Analysis on Pore Structure and Modeling of Hydration of Magnesium Phosphate Cement Paste

Magnesium phosphate cement (MPC) paste is hardened by the acid–base reaction between magnesium oxide and phosphate. This work collects and evaluates the thermodynamic data at 25 °C and a pressure of 0.1 MPa and establishes the hydration reaction model of MPC pastes. The influence of the magnesium–phosphorus molar (M/P) ratio and water-to-binder (W/B) ratio on the hydration product is explored by the thermodynamic simulation. Following this, the initial and ultimate states of the hydration state of MPC pastes are visualized, and the porosity of different pastes as well as fractal analysis are presented. The result shows that a small M/P ratio is beneficial for the formation of main hydration products. The boric acid acts as a retarder, has a significant effect on lowering the pH of the paste, and slows down the formation of hydration products. After the porosity comparison, it can be concluded that the decreasing of M/P and W/B ratios helps reduce porosity. In addition, the fractal dimension Df of MPC pastes is positively proportional to the porosity, and small M/P ratios as well as small W/B ratios are beneficial for reducing the Df of MKPC pastes.

Preparation and Properties of Magnesium Phosphate Cement-Based Fire Retardant Coating for Steel.

Magnesium phosphate cement (MPC) is a potential inorganic binder for steel coating due to setting and hardening rapidly, and bonding tightly with steel. NH4H2PO4-based MPC as a fire-retardant coating for steel was investigated in this work. MPC coatings were prepared from MPC paste and MPC mortar with expanded vermiculite (EV). The physical-mechanical properties and fireproof performance of MPC coatings were investigated in detail. An infrared thermal imager was employed to collect the temperature distribution and temperature rise with time on the coating samples automatically. The X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) analyses were carried out on the MPC coating after the fireproof test. Re-fire test and corrosion resistance were performed preliminarily on the MPC coating. The results showed that the fireproof performance of MPC coating met the fire protection requirement for steel as long as the thickness of the MPC paste coating was up to 10 mm, while the thickness of MPC mortar coating decreased to 4 mm when adding 40% EV (by mass). Dehydration and decomposition of reacted products in the hardened MPC coating were, to some extent, contributed to the excellent fireproof performance during the fire test. The slight ceramic formation and integration of MPC coating during the fire test would compensate for the decreasing of strength due to the dehydration and decomposition, so that the MPC coating would keep certain fireproof performance when undergoing fire again. MPC is suitable for a fire-retardant coating, while higher tensile bonding strength with steel and potential corrosion resistance on steel, as well as rapid surface drying and hardening can be achieved.

Fresh properties and compressive strength of MPC-based materials with blended mineral admixtures

To explore the feasibility of using blended mineral admixtures to improve the performance of magnesium phosphate cement (MPC) composites, fly ash (FA) + ground granulated blast furnace slag (GGBS) and fly ash (FA) + silica fume (SF) were used to partially replace the MPC, respectively, in this study. Their effects on the setting time and flowability of MPC paste and the compressive strength of MPC mortar (MPCM) were investigated through setting test, flowability test, and compressive test. The test results showed that the blended FA and GGBS adversely affected the setting time of MPC paste but slightly improved the flowability of MPC paste and the compressive strength of MPCM if an appropriate content was used. And the blended FA and SF adversely affected both the setting time and flowability of MPC paste. However, compared to the MPCM without any mineral admixture or with SF (FA) alone, the 25 % FA+ 5 % SF, 32.5 % FA+ 7.5 % SF, and 35 % FA+ 5 % SF could further enhance the compressive strength of MPCM. In addition, the XRD and SEM tests showed that the blended FA and GGBS mostly resulted in loose microstructure of MPCM. However, an appropriate content of blended FA and SF could lead to the formation of a dense microstructure, and a new magnesia-silica gel substance (MgSiO3) was generated, which improved the compactness and compressive strength of MPCM.

Experimental research on saline soil erosion resistance of magnesium phosphate cement pastes

The durability of concrete structures is affected by dry-wet and freeze–thaw cycling, and erosion by saline soils, such as those common to western China. In this study, the anti-erosion properties of magnesium phosphate cement paste (MPC) in salinized soil were investigated. The influences of the magnesium-to-phosphorus ratio (M/P), water-to-cement ratio (W/C), borax-to-magnesium ratio (B/M) and fly ash admixtures were studied in MPC specimens subjected to dry-wet cycle tests in water and saline solutions, with naturally cured specimens used as controls. The compressive strength of MPC was analysed by range analysis, analysis of variance and factor index analysis under various numbers of dry-wet cycles. Mass losses were quantified, morphologies were observed, and X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TG-DSC) were used to assess MPC before and after erosion. It was found that M/P and B/M were the major influences on the compressive strength of MPC. In MPC under natural curing, M/P was a strong influence on strength, while in MPC in water and saline solution, B/M was more important. The MPC slurry was most resistant to saline soil erosion with a 20% fly ash admixture, M/P = 2.5, borax admixture = 0.09 and water-cement ratio = 0.17. After dry-wet cycling, the MPC’s mass in water gradually decreased while that in saline solution gradually increased. With 40% fly ash, the compressive strength corrosion resistance coefficient of MPC placed in saline solution for 180 dry-wet cycles was 78.28%, indicating that a moderate amount of fly ash can enhance the saline soil anti-erosion performance of MPC. According to TG-DSC and XRD analyses, when MPC was subject to dry-wet cycling in water, the content of MgKPO4·6H2O(MKP) was the highest. The content was lower under natural curing and lowest in the saline solution. According to SEM, the degree of hydration of MPC was higher under dry-wet cycling than under natural curing, but the crystal structure of MKP was loosely arranged, which reduced the strength of the MPC.