An Important Film: Polychromy in the Pier Luigi Nervi Halls at the Turin Exhibition Center

Hidden by several layers of white paint,the almost forgotten polychromy of Nervi’s exhibition halls emerges from historical images,not necessarily intended to document the complex,but rather as a setting for exhibitions,fairs or film and advertising sets.Historical documentation reveals Nervi’s presence on the building site and his desire to supervise the finishing phases.The first stratigraphic investigations also testify to his attention color,as well as the subsequent transformations of use.Specific theoretical and technical issues regarding the conservation of the pictorial layers in relation to the conservation of the reinforced concrete elements are outlined.Furthermore,the use of polychromy in combination with the original employment of natural and artificial light sources introduces new facets into the analysis of Nervi’s work,offering the opportunity for original reflection.This is particularly true if we consider the impact of the interventions carried out so far,even those considered non-invasive,such as routine maintenance operations and some technological upgrades.

Response of masonry systems against blast loading

In this paper eight successive experimental blast tests with an increasing TNT equivalent charge weights ranging from 0.56 kg to 17.78 kg were conducted on unreinforced,ferrocemented overlay masonry and confined masonry walls.The pressure-time history caused by the blast was recorded by pressure sensors installed on the test specimen.The resulting damage pattern was observed during each test.Weak zones in the three systems of masonry were identified.Scaled distances for different damage levels in the three masonry systems were experimentally obtained.The results provide a basis for determining the response of each masonry system against blast loading.Consequently,efficiency of ferrocemented overlay masonry and confined masonry was found established in mitigation against blast loads.

Experimental Investigatin of Cementitious Slabs Rinforced with Wired-Meshes and Continuous CFRP Slices

Bending tests were conducted on 23 ferrocement slab specimens with steel meshes and continuous CFRP fibers. Two, or three, or four CFRP slices are gathered as a rope and hence these ropes are arranged to form a grid tied to a skeletal frame. The three patterns of slice reinforcement were used to reinforce cementitious slabs with or without conventional wire mesh reinforcement. The slabs were square and simply supported at their periphery with a clear span of 400 mm, and concentrically patch loaded to failure. For specimens designed to fail in flexure, the specimens reinforced with CFRP slices showed a smoother load deflection response and higher flexural capacity. For slabs designed to fail in punching shear, adding CFRP slices showed significant improvement in the ultimate shear capacity and ductility over reference specimens. Well distributed fine cracks of smaller width than control specimens were developed and no matrix spalling was observed.

Sturdy,Durable,Fast-To-Build,and Low-Cost Ferrocement Houses

This paper presents the experience in building low-cost houses in ferrocement technology,arched cross-section with on-site construction,using skeletal method combined with steel hollow structural sections.The author wanted to develop a simpler,faster and more cost-effective system of the construction of smaller buildings,retaining their stability and durability,energy-efficiency and resistance to earthquakes and storm winds at the same time.The goal was to enable non-professionals to build houses in quick and simple way using standard,easily accessible materials and tools.Houses such as described in this paper were built in DR Congo(Democratic Republic of the Congo)and have proven to be,fast-to-build,safe,durable and serviceable with practically no maintenance required.In 2016,15 such houses were built in less than four months.The author has promoted the solution for construction of such houses in continent climate conditions too,using stronger frame and much better thermal insulation,without thermal bridges.

Behaviour of Reinforced Concrete Columns Strengthened with Ferrocement under Compression Conditions: Experimental Approach

This paper reports a study based upon experimental investigation which aims to assess the behaviour of reinforced concrete columns strengthened with a new configuration of steel wire mesh as part of ferrocement layer under the action of axial compression loads. Square and circular small scale columns with three different slenderness ratios of 5, 6.7 and 10 were adopted. A comprehensive experimental progarmme was then running to measure the load capacity and both lateral and vertical displacements. The failure mode was also monitored for each tested case. The results obtained was compared with the reference column samples (without wire mesh) and with some expressions suggested by ACI Code. The experimental results showed that the most influential parameter on the property of load carrying capacity is the slenderness of column. As the slenderness increases, the load capacity clearly decreases. The use of wire mesh enhanced the capability of column to resist the axial loads due to confinement role provided by such material. The maximum percentage increase in load carrying capacity for the modified columns compared with those for the reference samples was 53% for the circular column at slenderness ratio of 10. The critical path of the failure mode was similar for all of the tested columns and normally began from the top or bottom ends, then, in some cases, passed through the middle zone of the column. A suitable expression was suggested to be used for calculating the modulus of elasticity of the tested column based upon the value of load carrying capacity under compression loads.

Finite Element Analysis (FEA) for the Beam-Column Joint Subjected to Cyclic Loading Was Performed Using ANSYS

This paper analyses the seismic performance of exterior beam-column joints strengthened with unconventional reinforcement detailing. The beam-column joint specimens were tested with reverse cyclic loading applied at the beam end. The samples were divided into two groups based on the joint reinforcement detailing. The first group (Group A) of three non-ductility specimens had joint detailing in accordance with the construction code of practice in India IS456-2000, and the second group (Group B) of three ductility specimens had joint reinforcement detailed as per IS13920-1993, with similar axial load cases as the first group. The experimental studies are proven with the analytical studies carried out by finite element models using ANSYS. The results show that the hysteresis simulation is satisfactory for both un-strengthened and ferrocement strengthened specimens. Furthermore, when ferrocement strengthening is employed, the strengthened beam-column joints exhibit better structural performance than the un-strengthened specimens of about 31.56% and 38.98 for DD-T1 and DD-T2 respectively. The analytical shear strength predictions were in line with the test results reported in the literature, thus adding confidence to the validity of the proposed models.

Calculation of diagonal section and cross-section bending capacity for strengthening RC structure using high-performance ferrocement laminate

Because there is a great demand of reinforce-ment and retrofitting of aged structures nationwide,as well as the rapid development of innovative building materials,the adoption of strengthening RC structures using new inorganic materials has become possible.High-performance ferrocement laminate(HPFL)is an effective method of strengthening concrete structure.High-performance ferrocement laminate is a new type of inorganic material with the advantages such as high strength,small contraction,good bonding properties,etc.This paper introduces the formula of cross-section bending capacity for strengthening concrete beams with HPEL.A comparative analysis of experimental data,as well as the calculation of diagonal section bearing capacity of concrete members,is given.

Estimating moment capacity of ferrocement members using self-evolving network

In this paper, an empirical model based on self-evolving neural network is proposed for predicting the flexural behavior of ferrocement elements. The model is meant to serve as a simple but reliable tool for estimating the moment capacity of ferrocement members. The proposed model is trained and validated using experimental data obtained from the literature. The data consists of information regarding flexural tests on ferrocement specimens which include moment capacity and cross-sectional dimensions of specimens, concrete cube compressive strength, tensile strength and volume fraction of wire mesh. Comparisons of predictions of the proposed models with experimental data indicated that the models are capable of accurately estimating the moment capacity of ferrocement members. The proposed models also make better predictions compared to methods such as the plastic analysis method and the mechanism approach. Further comparisons with other data mining techniques including the back-propagation network, the adaptive spline, and the Kriging regression models indicated that the proposed models are superior in terms prediction accuracy despite being much simpler models. The performance of the proposed models was also found to be comparable to the GEP-based surrogate model.

Sound transmission performance on cavity ferrocement panels with ties

Ferrocement panels have been used in low cost housing construction in developing countries. This study focuses on the sound transmission performance of cavity ferrocement panels with ties. In this study, panels have been cast and tested in transmission loss suite specially designed and constructed for testing their sound transmission performance experimentally. The measured results agree well with the theoretical model.