PROPOSAL FOR IMPROVEMENT TO THE ACI 211.1 – 22 SELECTING PROPORTIONS GUIDE BY USING A/C RATIO VALUES ACCORDING TO THE IP-30 AND IP-40 CEMENT TYPE TO ACHIEVE THE REQUIRED DESIGN STRENGTH (F’CR)

Abstract

Concrete is key in construction, but its production (8% of global emissions) significantly impacts the environment. This research optimizes the dosage according to ACI 211.1 for IP-30 and IP-40 cements (locally available), resolving discrepancies between required (f'cr) and actual (f'c) strength that generate cost overruns. The hypothesis proposes that adjusting the water/cement ratio (A/C) according to IP cement type will reduce these differences.
Methodologically, 192 specimens were evaluated with a mixed approach (quantitative/qualitative). Initial results with A/C=0.56 showed actual strengths of 290.16 kg/cm² (IP-30) and 342.02 kg/cm² (IP-40) versus f'cr=294 kg/cm² (for f'c=210 kg/cm²), showing greater discrepancy in IP-40. After adjusting the A/C ratio to 0.55 (IP-30) and 0.69 (IP-40), resistances of 295.19 kg/cm² and 296.51 kg/cm² respectively were achieved, improving precision and reducing differences.
Its impact lies in optimizing the use of materials (reduction of ≈15-20% cement), mitigating associated CO₂ emissions, saving due to less waste, improving consistency in resistance.
But it is limited in that it requires validation in real conditions and its analysis is limited to two types of cement.
The adaptation of the A/C ratio according to IP cement significantly improves the dosing accuracy, demonstrating that small adjustments in standardized methods can optimize sustainability in construction.