Development of fiber-reinforced heavy-weight self-compacting mortars with special protection properties against ballistic missiles
Self-compacting mortars possess a high potential for accomplishing significant gains in engineering performance and economy owing to the elimination of vibration. The key factor in their development is to ensure sufficient flowability and segregation resistance. Proper rheology of fresh mortars must be ensured by suitable combination of cement and additives. Fibers incorporated into mortar composition serve as a reinforcement and could even lead to complete substitution of conventional reinforcement. Improved durability of material can be attained because of enhanced post-cracking tensile capacity and more diffused cracking process with smaller widths. Composite material strength, fibre content, its geometry and type, distribution and orientation of fibres within the cement matrix at the end of placing belong among important factors influencing performance of heavy-weight self-comacting mortars.
The perspective application of fiber-reinforced heavy-weight self-compacting mortars could be found in the civil security as a protection against ballistic hip, which was confirmed also by our preliminary experimental results realized in coordination with BOGGES, spol. s r.o., specialist in testing and certification of vehicle, personnel and critical infrastructure ballistic protection.
The steps required to attain the main objective include:
• optimization of particle size distributions of initial materials,
• selection of type and size of fibers, optimization of grading curve of fillers,
• optimization of binder composition based on the rheological properties of fresh mortars influenced by water to binder ratio and suitable types of chemical admixtures,
• determination of mechanical properties and ballistic characteristics,
• evaluation of physical and chemical properties.
Fig.1. TG/DTG curves (left) and development of schrinkage of fiber-reinforced heavy-weight self-compacting mortars (right).