Why is moisture content measurement important when assessing the health of a timber bridge?
Moisture content measurement is crucial when assessing the health of a timber bridge because it directly influences the susceptibility of the wood to decay and insect infestation, as well as affecting its strength. High moisture content (typically above 20%) creates an environment conducive to the growth of decay fungi, which break down the wood's cellular structure, leading to strength loss. Similarly, many wood-boring insects thrive in moist wood. Additionally, the strength of wood decreases as its moisture content increases above the fiber saturation point (around 25-30%). Therefore, monitoring moisture content helps identify areas at risk of decay or insect attack, allows for timely implementation of preventative measures, and provides a more accurate assessment of the timber's structural capacity. Measuring moisture content can be done using handheld moisture meters, which provide a quick and convenient way to assess the condition of timber members.