Combined effect of partial replacement of cement with Alccofine and Fly Ash in M40 Grade Concrete

ABSTRACT
The excessive use of Ordinary Portland Cement (OPC) production is one of the major contributors to global
carbon dioxide emissions and environmental degradation, accounting for nearly 7–8% of global CO₂ emissions
[11, 23, 24, 45]. To mitigate the environmental impact associated with cement production, the construction
industry has increasingly focused on sustainable alternatives that reduce cement consumption while maintaining
the desired mechanical and durability performance of concrete [13,14,26]. Supplementary cementitious
materials (SCMs), such as Fly Ash and Alccofine, have demonstrated considerable potential in enhancing
concrete properties while minimizing environmental impact [1–3,12,16,19]. This study investigates the combined
effect of Alccofine-1203 and Fly Ash as partial replacements for cement in M40 grade reinforced cement concrete
(RCC).
A fixed Alccofine-to-Fly Ash ratio of 33.33:66.67 was adopted, and the total cement replacement level was varied
from 0% to 50%. The concrete mixes were evaluated for fresh, mechanical, and durability properties, including
slump, compressive strength, split tensile strength, flexural strength, and water absorption, in accordance with
relevant Indian and ASTM standards [31–33,38,40–42]. The experimental results revealed that workability
increased with increasing SCM content due to improved particle packing and lubrication effects. Among all the
mixes, the concrete containing 10% Alccofine and 20% Fly Ash exhibited optimum performance, achieving the
highest 28-day compressive strength of 43.55 MPa along with improved tensile and flexural strengths and
acceptable durability characteristics. At higher replacement levels, a reduction in strength was observed due to
dilution effects and delayed pozzolanic reactions [12,20,27,28]. The findings of this study demonstrate that the
combined utilization of Alccofine and Fly Ash can effectively reduce cement consumption while maintaining or
enhancing the performance of M40 grade RCC