Determination of the age of cracks is an important issue. For instance, millions of dollars are spent on arbitration and litigation arising from damage claimed to have been produced by some recent adjacent activity such as heavy traffic, construction, blasting, etc. or some recent natural phenomenon, such as an earthquake, hurricane, flood, etc. Once the crack is identified as a concern, focus most often turns to an investigation of the age of the crack relative to the time of the unusual event. Such age dating would then allow more precise linkage to causation. Current methods used to date cracks are often subjective, limited in their application and yield a relative age, rather than an absolute age.
The research will investigate a new biological method to determine crack age. It will specifically determine the feasibility of sampling of biota from a crack surface. Success in this initial phase will form the foundation which will allow the complete study of the hypothesis that the amount of biomass on a given surface is an indication of the amount of time that has passed since the surface was exposed. The hypothesis is based upon the premise that the change in the amount of biomass on a surface over time can be quantifiably measured. A comparable procedure with macroorganisms, such as insects, is currently used in forensic science to determine time of death.
The procedure combines two rarely connected fields in science: microbiology and construction/materials engineering to establish the crack age from the accumulation of biomass. Preliminary work shows that common laboratory procedures can be applied to the construction materials of interest. The research exploits biological laboratory testing procedures by applying them in a new approach. The research explores the process of microbial colonization of new, sterile surfaces introduced into the natural environment by cracking of already present construction materials. Attention is focused on obtaining relevant information with basic laboratory facilities, while avoiding expensive equipment or time-consuming investigations.
This research promotes interdisciplinary interaction between two rarely connected fields of study, biology and construction/materials engineering. It could reduce or even eliminate millions of dollars spent in litigation surrounding the appearance of cracks. Should the research prove successful, it will fuel further application of bio-methods in the field of construction. The procedure addresses a problem present in virtually every facility ever constructed and promotes understanding of material responses by relating the time of cracking to any unusual activities that may have occurred in the same time period. Quantification of crack age will reduce the tens of millions of dollars spent each year in litigation over causes of cracks. By pinpointing the time of cracking, the work will also allow comparison of effects from natural changes in the environment and surrounding anthropomorphic activities.