Use of Alkali Activated Mortar with Ceramic Waste for High Temperature Applications

Abstract

High strength concrete is prone to fire hazards. At 4000C, the C-S-H gel tends to disintegrate into quick lime powder causes the spalling phenomena which can decrease the load carrying capacity of structural members, thereby, losing the structural integrity of the structure which can cause financial as well as human losses at large scale. So, the use of fireproofing materials which acts as a thermal barrier is needed for protection of structures from fire. High thermal stability of ceramic products due to its firing at high temperatures and rich source of aluminosillicate binder, it can be a viable solution when activated with alkalis like Sodium Hydroxide(NaOH) and Sodium Sillicate(Na2SiO3) has proved to be of good structural fire resistance application. Fire resistance of Alkali Activated Mortar comprising of ceramic waste in high proportion is studied( up to 70%) replacement of binder content is studied. A preliminary study was carried out by varying different type of ceramic waste. Ten various mix designs with three different type of ceramic wastes(Sanitary ware waste, Vitrified Tile Waste and Polishing waste) and different cementetious material like Fly Ash and GBFS were used with same molarity (4M) of NaOH and same solution to binder ratio. Waste which gives having maximum compressive strength was chosen for final investigation. Further, the effect of varying alkali activation parameters in alkali activated mortar is studied. Those parameters were Sodium Hydroxide(NaOH) concentration(6M,10M) and Sodium Sillicate to Sodium Hydroxide ratio(0.75,1.5,2), with cementetious material GBFS and Sanitary Ware waste. Twelve mixes were finalized varying the concentration of Sodium Hydroxide, NS:NH ratio and proportion of Sanitary Ware waste and cubes of size 50mm x 50mm x 50mm are casted and heated to elevated temperature of 9000C for 1 hour and then they were tested for workability, compressive strength, residual compressive strength and mass loss after fire exposure is evaluated and optimum mixture design is further tested for thermal conductivity and the suitability of alkali activated mortars is tested as per EFNARC guidelines of materials for passive fire protection of tunnel linings. Conclusion is made, based on the result of Mechanical and thermal properties of all twelve finalized mixes .Result is shown in graphical form and discussion is done to show the enhancement of properties of Alkali Activated Mortar by varying different parameters of alkali activation and proportion of Ceramic waste as a replacement to GBFS in the design of alkali activated mortar. Thermal resistance of mortar increased with increase in proportion of ceramic waste in mortar. Mild steel plates coated with thin coatings with ceramic waste is also prepared Adhesive strength of coating is determined by pull off test to check the efficiency of paste as coating material for steel structures. For validation, numerical investigation is also carried out using finite element(FE) based software ANSYS.Heat transfer analysis is being done and temperature at interface at each interval of time is measured and compared with analytical results.