Hygric Properties of Machine-Made, Historic Clay Bricks from North-Eastern Poland (Former East Prussia): Characterization and Specification for Replacement Materials

Abstract

This paper deals with the hygric characterization of early 20th century machine-made clay bricks, representative of great number of historical buildings in north-eastern Poland. Heritage buildings have a high potential for adaptive reuse, which is strictly connected with an urge for knowledge about the properties of these existing building envelopes. To better understand the hygric behavior of historic buildings, various experimental laboratory tests, including density, water absorption, compressive strength and freeze-thaw resistance, were conducted. In order to assess the microstructural characteristics of the tested bricks, mercury intrusion porosimetry (MIP) and X-ray micro-computed tomography (micro-CT) tests were performed. These tests were conducted on clay bricks from historic buildings, as well as on those that are currently being produced, in order to identify the relationship between the materials used in the past and the replacements produced presently. This paper addresses the lack of systematic application of existing standards for evaluating the state of the conservation of historic bricks and for establishing the specifications for replacement bricks. The results of conducted study and further research will be the basis for creating a historic materials database. It would be a useful tool for selecting bricks that correspond with the historically used materials and help to maintain homogenous structure of the restored buildings.

Comparative Analysis of the Thermal Conductivity of Handmade and Mechanical Bricks Used in the Cultural Heritage

“…The necessary material was obtained from buildings dating from the 19th and early 20th centuries, which at that time were being renovated or partially demolished, making it possible to obtain pieces from their walls. The sampling method from existing structures and the choice of bricks were based on the results of previous research carried out in the buildings, and the brick characteristics and manufacturing processes [ 11 , 27 , 28 , 29 , 30 ].…”

“…The materials obtained were selected according to their manufacturing process in 3 groups (handmade, extruded and pressed), in order to be able to relate their characteristics to the conductivity of the brick samples studied [ 30 ]. Within each group, the bricks were classified by type of brick into 6 subgroups, according to their origin and dimensions, with those of similar shapes being selected, which were subsequently used for the manufacture of the different test pieces.…”

A Comparative Study on Hygric Properties and Compressive Strength of Ceramic Bricks

“…The examples cited above from the literature on the factors affecting the durability of masonry clearly demonstrate the need to perform tests on the material’s ability to moisture transport, absorption and compressive strength of the masonry element. The problem of assessing the technical condition of existing buildings, in which clay bricks are the main structural element, is all the time relevant [ 32 , 33 , 34 , 35 ]. In particular, when materials are sought for the reconstruction of an existing element or when the reuse of post-demolition material is considered [ 36 , 37 , 38 , 39 ].…”