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

Abstract

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.

Cold-Sprayed Composite Metal-Fluoropolymer Coatings for Alloy Protection against Corrosion and Wear

“…However, the most rational, effective, and inexpensive method of protection is the application of coatings [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. It is possible to use a paintwork material [13,19,30] (including those with additives of nanoparticles [25,[31][32][33][34][35][36][37][38] and inhibitors [13,14,20,[39][40][41][42][43][44][45][46][47]) and zinc coating to protect the material against its intensive destruction [48].…”

The partial fire protection of steel members: a comparative study

“…These cracks enlarge with time and can cause entire sections of the spray to fail (Jaya Kumar et al. , 2022; Dai et al. , 2022).…”

“…When excessively large amounts are used, the insulating properties of the spray can deteriorate, and microcracks can form immediately after application of the spray. These cracks enlarge with time and can cause entire sections of the spray to fail (Jaya Kumar et al, 2022;Dai et al, 2022).…”

High-Temperature Resistance of Modified Potassium Magnesium Phosphate Cement

“…Vijin et al [20] studied the ability of magnesium phosphate cement (MPC) coating to protect steel structures and found that no MPC coating peeled off during 45 min of burning under the flame. Dai et al [21] prepared a magnesium phosphate cement coating by mixing it with expanded vermiculite to study the physical and mechanical properties and fire performance of MPC coating. It was found that when the MPC coating thickness reached 10 mm, its fire performance met the fire resistance requirements of steel structures.…”