Vulnerability of historic buildings to environmental actions; an empirical methodology

The following dissertation sets out a methodology for empirically determining the response of historic building fabric to exposure to weathering by the climate conditions wind driven rain and flood. Historic structures are inherently vulnerable to moisture ingress in that they are typically composed of porous materials, which naturally absorb moisture. Ingress leading to heightened moisture content causes decay and damage in the fabric, which can lead to deterioration in the mechanical behaviour of the material and construction systems. In recent years the trends observed in the climate suggest that environmental conditions are changing such that the hazard posed to historic buildings from moisture ingress will increase, due to an increase in frequency and severity of heavy precipitation events and floods. In light of this there is an identified need to determine the scale of the effect that this change in hazard could potentially have on the deterioration of historic structures. The experimental programme designed and implemented here is novel in the respect that it brings together the simulation of climate conditions with test specimens formed from original historic building fabric. The analysis of the data is further novel in that it directly correlates climate hazard severity with mechanical behaviour. The findings of the experimental programme confirm that for the majority of cases increased exposure leads to increased reduction in strength and stiffness, although due to complexities relating to absorption, increased hazard does not always translate into increased risk. The work achieves the quantification of the relationship between hazard and vulnerability, and enables the production of empirical fragility curves suitable for use in the risk assessment of historic structures. The work therefore sets out a methodology that can be used in the future to quantify the resilience of historic buildings to climate change using laboratory techniques.