This paper shows the results of an experimental analysis on the bell tower of “Chiesa della Maddalena” (Mola di Bari, Italy), to better understand the structural behavior of slender masonry structures. The research aims to calibrate a numerical model by means of the Operational Modal Analysis (OMA) method. In this way realistic conclusions about the dynamic behavior of the structure are obtained. The choice of using an OMA derives from the necessity to know the modal parameters of a structure with a non-destructive testing, especially in case of cultural-historical value structures. Therefore by means of an easy and accurate process, it is possible to acquire in-situ environmental vibrations. The data collected are very important to estimate the mode shapes, the natural frequencies and the damping ratios of the structure. To analyze the data obtained from the monitoring, the Peak Picking method has been applied to the Fast Fourier Transforms (FFT) of the signals in order to identify the values of the effective natural frequencies and damping factors of the structure. The main frequencies and the damping ratios have been determined from measurements at some relevant locations. The responses have been then extrapolated and extended to the entire tower through a 3-D Finite Element Model. In this way, knowing the modes of vibration, it has been possible to understand the overall dynamic behavior of the structure.

Raw earth is one of the oldest building materials, which is suitable for various uses: from the construction of load-bearing walls to use for plasters and finishes. The presence of straw fibers can give different behavior to this material. The present paper illustrates preliminary sensory and qualitative analyses, and subsequent laboratory tests that allow the characterization of the raw earth material with straw fibers for rammed earth constructions through mechanized compaction and the identification of a compatible earth mortar. The raw material considered in this study is mainly clayey; for this reason, a mix design usable with the pisé (or clay) technique has been developed. Cylindrical samples have been made through a press and subject to unconfined compression and indirect tensile tests. The results of the tests showed consistent tensile and compressive strength values in the context of earth materials. At the same time, a study for the realization of a mortar with the same base soil was carried out considering four mixtures, in order to investigate the best compromise between workability, shrinkage and compressive strengths. The purpose of the study was to investigate the mechanical characteristics of the local material through preliminary and laboratory tests, to classify it according to the Unified Soil Classification System (USCS) and to verify its suitability for a possible use in the construction field.

In this paper, recycled polyethylene terephthalate (PET) was used to produce eco-innovative engineering materials with optimized performance, minimizing the environmental impact deriving from plastic consumption activity and limiting the continuous consumption of raw materials. The recycled PET obtained from waste bottles, commonly used to improve the ductility of concrete, has been used with a different weight percentage as plastic aggregate in the replacement of sand in cement mortars and as fibers added to premixed screeds. In detail, the effect of PET treatment (chemical or mechanical) on the thermal performance was evaluated. Non-destructive physical tests were conducted to determine the thermal conductivity of the investigated building materials. The performed tests showed that chemically depolymerized PET aggregate and recycled PET fibers derived from plastic wastes can reduce the heat conduction capacity of the cementitious materials with limited reduction in compressive strength. The results of the experimental campaign have made it possible to evaluate the influence of the recycled material on the physical and mechanical properties and its feasibility in non-structural applications.

The paper shows the results of an experimental tests campaign carried out on concretes with recycled aggregates added in substitution of sand. Sand, in fact, has been totally replaced once by blast-furnace slag and fly ashes, once by blast-furnace slag and microsilica. The aim is both to utilize industrial by-products and to reduce the use of artificial aggregates, which impose the opening of pits with high environmental damage. The results show that in the concretes so made the water absorption capacity has reduced and durability has improved. The test campaign and the results described in the present article are certainly useful and can be especially utilized for research on a larger scale in this field.

The increasing consumption of plastics has necessitated the need to find a sustainable solution to reuse PET within common building materials. Recycled PET reinforcement would reduce plastic waste that is difficult to dispose of and CO₂ emissions, representing a sustainable solution for generating lighter building materials. The goal of this work was to define a new cementitious mixture design and to study the mechanical and thermal behavior of three typologies of screeds with fine recycled polyethylene terephthalate (PET) aggregates. A weight percentage of PET of 1%, 2%, and 3% was used. The test results for sustainable screeds (S-Screeds) with waste PET were compared with a reference screed without the addition of plastic. In the fresh state, the workability and the air content were measured, while in the hardened state, the density, thermal conductivity, and compressive and flexural strength were investigated. These properties showed improvement for some tested S-Screeds after the introduction of fine (a few millimeters in size) and irregularly shaped waste plastic aggregates. Scanning electron microscopy (SEM) analysis showed the presence of a release surface between the cementitious mixtures and the plastic material, even if the mechanical interaction between the matrix and PET still existed.