Luigi Mollo

Moisture Measurements in Masonry Materials by Time Domain Reflectometry

Time domain reflectometry (TDR) has been evaluated as a tool for the measurement of the moisture content of masonry materials. To this aim, the relationship between relative dielectric permittivity, measured by TDR, and volumetric water content, measured gravimetrically, has been experimentally determined over samples of three cement mortars and a clay brick. The obtained experimental points do not fit the calibration curves available in literature for other porous materials, such as soils and rocks. Instead, specific calibration relationships have been determined. The obtained results show that in all cases dielectric permittivity is highly sensitive to moisture variations, indicating TDR as a promising tool for moisture measurement of building materials. Owing to the feasibility of the proposed experimental procedure for moisture measurements of real masonry walls, the technique appears to be suitable for field monitoring applications.

Use of TDR to Compare Rising Damp in Three Tuff Walls Made with Different Mortars

AbstractCapillary rise is a serious phenomenon that may have potentially devastating consequences within buildings (biological corrosion, worsening of indoor comfort parameters, worsening of therma...

Moisture Measurements In Masonry Materials Using Active Distributed Optical Fiber Sensors

A Brillouin Optical time-domain analysis (BOTDA) sensor has been used to perform distributed temperature measurements along a fiber optic cable with an electrically conductive armoring heated via electrical resistance. The thermal response of a fibre-optic probe put in contact with yellow tuff samples at different moisture content is measured by the BOTDA sensor, paving the way to distributed measurements of moisture content in masonry materials.

Influence of cement/sand ratio on behavior of cement mortar

Purpose – The purpose of this paper is to investigate the influence of cement/sand ratio on behaviour of cement mortar. Design/methodology/approach – Literature review was used to confirm that the cement/sand ratio have influence on the mortar strength and that its influence is not very studied. The literature points out also that the constitutive model of mortar is very important in the structural design of masonry but it has not been investigated much. Findings – The results of study allow to forecast the mortar strength by the cement/sand ratio when the water/cement ratio is fixed (0.50). Besides, the obtained experimental results allow defining a constitutive model for sand mortar. Research limitations/implications – Other experiments would be proper to extend the research field. Practical implications – The findings are of particular importance to mix design of cement mortar and to structural design of masonry. In fact, for mortar in the practices, there are no constitutive equations to use in the st...