Comparing the moisture permeability of limecrete and concrete floor slabs

Author(s): Grace A. Phillips, Kevin Briggs, Iain McCaig, Richard J. Ball
Paper category: Proceedings
Book title: Proceedings of the 5th Historic Mortars Conference
Editor(s):José Ignacio Álvarez, José María Fernández,Íńigo Navarro, Adrián Durán, Rafael Sirera
ISBN:978-2-35158-221-3
e-ISBN: 978-2-35158-222-0
Publisher: RILEM Publications SARL
Publication year: 2019
Pages: 1267-1278
Total Pages: 12
Language : English

Abstract: Retrofitting impermeable ground-bearing floor slabs to an old building is thought to ‘drive’
soil moisture up adjoining walls. Historic England has commissioned the University of Bath to
conduct research into water vapour and liquid permeation through typical floor slab
materials, and their influence on local soil moisture. The project comprises computer
modelling to examine the response of soil moisture to slab installation, laboratory tests to
analyse moisture movement rates through slab materials, and field monitoring to measure
the effect of different slab materials in situ. Initial laboratory tests on two materials,
concrete and NHL5-based limecrete, used a bespoke modular soil-slab-air apparatus
developed to establish evaporation rates through slab materials. Subsequent material
characterisation tests were conducted to compare their microstructural properties and
moisture transfer characteristics including mercury intrusion porosimetry (MIP), sorptivity
tests, and scanning electron microscopy (SEM). Preliminary results showed the NHL5-based
limecrete slab was only marginally more permeable than the concrete slab, suggesting that a
NHL5-based limecrete slab might be more effective than a concrete slab in reducing water
rise in a wall. Further testing of limecrete mixes and in situ monitoring is proposed to verify
these results.

Online publication : 2019
Publication type : full_text
Public price (Euros) : 0.00