Ignition and flame-growth modelling on realistic building and landscape objects in changing environments

Effective mitigation of external fires on structures can be achieved flexibly, economically, and aesthetically by (1) preventing large-area ignition on structures by avoiding close proximity of burning vegetation; and (2) stopping flame travel from firebrands landing on combustible building objects. Using bench-scale and mid-scale fire tests to obtain flammability properties of common building constructions and landscaping plants, a model is being developed to use fast predictive methods suitable for changing environments imposed on a parcel lot consisting of structures and ornamental plants. Eventually, the property owners and associated professionals will be able to view various fire scenarios with the ability to select building materials and shapes as well as select ornamental plant species and their placement for achieving the desired fire mitigation. The mathematical formulation presented at the 2006 BCC Research Symposium is partially shown here and some results are compared with (1) specialised testing of Class B burning brands (ASTM E108) in the cone calorimeter (ASTM E1354); (2) our refurbished and modified Lateral Ignition and Flame Travel Test (ASTM E1321 and E1317); (3) room-corner tests with oriented-strand board (ISO 9705); and (4) cone calorimeter tests of fire-resistive materials such as fire retardant-treated plywood and single-layer stucco-coated oriented-strand board. Additional keywords: calorimetry, fire mitigation, flammability modelling.