Sound transmission loss via wall ties

摘要

In this study tied and untied brick cavity walls with identical wythes are compared with respect to their sound insulative merit. The wythes were connected either at discrete intervals by unit ties, i.e. rectangular ties, RT, or brick bonder, BT,or were connected by continuous horizontal joint reinforcement, i.e, truss, TT, or ladder, LT, type reinforcement. The cavity width between the wythes was either 2 or 5 cm. Both of the wythes (thickness=8.5 cm) were constructed by 19×19×8.5 cm brickshaving horizontal cores, The cavity wapl was plastered on both sides by cement-based plaster (both base and finish coats), NP, having total thickness of 2 cm. Polystrene rigid foam boards P2(density, ρ=24 kg/m{sub}3, thickness, t{sub}a=2 cm) or P5(ρ=10kg/m{sub}3, t{sub}a=5 cm) were placed in the cavity Even though, wall ties provide greater strength to the walls against lateral forces, they cause an adverse effect on sound transmission loss, TL, of the walls. RT and LT cause respectively a decrease of3.44 dB and 4.05 dB in the mean TL value of the walls.