Experimental Investigation of Interaction Effects of Integral Waterproofing Admixtures and Naphthalene-Based Superplasticizers on Fresh and Hardened Concrete

Abstract

This study experimentally investigates the interaction between integral waterproofing admixtures and naphthalene-based superplasticizers in concrete, addressing limited evidence on their combined effects on fresh and hardened properties. A commercially adopted mix with varying admixture dosages was evaluated for slump, setting time, density, water absorption, compressive strength, and tensile splitting strength. Unit weight and density remained unchanged. Slump and setting times increased with superplasticizer dosage, while the waterproofing admixture showed minimal influence on fresh properties. Mechanical strength improved at moderate superplasticizer dosages but declined at higher levels, particularly around 3% by cement mass. Water absorption remained largely comparable across mixes. The results confirm that superplasticizer dosage governs performance, and excessive dosages reduce mechanical capacity. Controlled proportioning is therefore essential to optimize workability, strength, and durability in liquid-retaining concrete applications.