Performance optimization of concrete modified with volcanic ash-based composite adhesive and finely dispersed mineral fillers

This study investigates the physical and mechanical properties, frost resistance, and bond strength to reinforcement of concrete incorporating a composite adhesive modified with finely dispersed volcanic ash, and determines the optimal mix design for B30 class concrete. The results reveal that the composite adhesive content is the key factor influencing compressive strength. Optimal parameters were established as 20-25 % mineral filler, a water-cement ratio of 0.25-0.28, and 440-450 kg/m 3 of composite adhesive, achieving a compressive strength of 48-49 MPa, which exceeds the B30 requirement (47.9 MPa). The modified concrete demonstrated frost resistance up to F300 and a bond strength of 6.2 MPa, nearly three times higher than that of conventional concrete. Heat-moisture curing further increased strength by 10-15 % compared to natural curing. The findings confirm that volcanic ash-based composite adhesive significantly improves strength, durability, and reinforcement adhesion, while reducing cement consumption by 130-150 kg/m 3 , ensuring both economic and environmental benefits for large-scale concrete production