Comparative Study on Mechanical Properties of Fiber-Reinforced Cement Mortars Using Fly Ash and Manufactured Sand
DOI:
https://doi.org/10.64252/e5xs9y49Keywords:
Cement mortar; Fly ash; Manufactured sand; Polypropylene fibers; Compressive strength; Flexural strength; Sustainable construction materials.Abstract
The depletion of river sand and the high carbon footprint of cement production makes it essential to use sustainable alternatives in mortar design. This study experimentally evaluates the influence of partial cement replacement with fly ash and substitution of river sand with manufactured sand (M-sand) on the compressive and flexural strength of fiber-reinforced cement mortars. Two mortar mix proportions, 1:3 and 1:4 (cement:sand), were considered and twelve mixes for each proportion were designed, cast and tested as per IS 2250:1981. For 1:3 mixes, cement was partially replaced with 6% fly ash (mixes 3,4,7,8,11,12). River sand was replaced with 50% M-sand (mixes 9,10,11,12) and 100% (mixes 5,6,7,8). Polypropylene fibers (0.25% by cement weight) were incorporated in mixes 2,4,6,8,10,12. For 1:4 mixes, 4% fly ash replacement was used in mixes 3,4,7,8,11,12 with the same M-sand replacement scheme and fiber additions with a constant water to cement ratio of 0.5. Compressive and flexural strengths were tested at 28, 56, and 90 days. Results revealed that mixes with fly ash, River sand, M-sand, and fibers improved mechanical properties, with best performance for 1:3 and 1:4 mixes containing 6% and 4% fly ash, blended sands, and fibers. The 1:3 mixes outperformed 1:4 blends, showing the viability of these sustainable materials.