Title: Pertinent Surface Moisture of Concrete for Water Ingress Assessment

Author(s): Uwazuruonye Raphael Nnodim

Publication: Materials Journal

Volume: 120

Issue: 5

Appears on pages(s): 89-100

Keywords: durability; permeability; pore size distribution; transport properties

DOI: 10.14359/51739018

Date: 9/1/2023

Abstract:
This study clarifies the effects of moisture (expressed as percentage saturation degree of permeable pore voids, PSD) on water ingress properties of concrete and establishes a region where PSD does not affect the quantitative water absorption. Experimental measurements and finite element model (FEM) simulation results for ordinary portland cement (OPC) concretes preconditioned to equilibrium moisture formed plateaus between 21 and 58% PSD. Non-continuous finer capillary pores (ϕ10 nm [3.937 × 10–4 mil, thou] to ϕ100 nm [3.937 × 10–3 mil, thou]) constitute the empty pores within the plateau region before tests. Water sorptivity of OPC and slag cement concrete blocks at several degrees of surface moisture with internal moisture gradients validate the existence of the plateau within the PSD range. Measuring short-term water absorption within this plateau region eliminates the effects of initial surface moisture content on the measured properties and evaluates the continuity and connectivity of pores, which is the major indicator of the durability of concrete.