MOLECULAR STRUCTURE AND ULTRASTRUCTURE Chemical constituents Chemical analysis reveals the existence of four constituents and provides data on their relative proportions. This information may be summarised as in Table 1 proportions are for timber in general and slight variations in these can occur between timber of different species, or in different parts of a single […]
Structure of Timber Structure of timber at macroscopic level The trunk of a tree has three physical functions to perform: firstly, it must support the crown, a region responsible for the production not only of food, but also of seed; secondly, it must conduct the mineral solutions absorbed by the roots upwards to the crown;
Durability of FRC Combining a continuously hydrating, highly alkaline matrix with a wide variety of types, shapes and sizes of reinforcing fibres will lead to complex, time-dependent fibre–matrix interactions. These interactions lead to the engineering properties of most FRC varying markedly with time. This was recognised by even the earliest modern FRC researchers, so the
Applications of FRC In this article we describe some typical applications for the various types of FRC. The list is not exhaustive – other FRC could be used for the applications given, and there are countless other applications for FRC – but they are intended to give you an idea of the major uses of
Manufacturing of FRC Cast premix By mass of FRC produced, casting of premixed FRC is probably the most common method, especially for secondary or tertiary FRC. Fibres are normally supplied in ‘pre-batched’ bags, with each bag suitable for direct addition to one cubic meter of concrete to provide the correct volume fraction Vf . Steel
FRC Reinforcement Layouts The manner in which fibres are distributed throughout an FRC component is determined largely by the manufacturing method. As with FRP, choosing the correct fibre layout or fibre architecture for a given loading case is crucial in order that the fibre can be used most efficiently. There are two key parameters: fibre
Component Materials of FRC FIBRE Almost every imaginable type of fibre has been used at some time or another with cement or concrete. The most commercially significant types are described below and their properties are summarised in Table 1. Here we focus on the properties particularly relevant to FRC. Polymer fibres Polymer fibres have been
During the introduction of FRP composites into the building and construction industry in the 1970s glass fibres were used in a polyester matrix as a construction material. Skeletal frames constructed from reinforced concrete (RC) or steel columns and beams were in-filled with non-load-bearing or semi-load-bearing GFRP panels manufactured by the wet lay-up process or by
Durability of Polymer Composites All engineering materials are prone to degradation over time and FRP materials are no exception to this rule. However we will see in this chapter that they do offer some significant durability advantages over the more conventional construction materials, although they are not without their own problems. The ageing of a
It is a good idea to begin the design of the foundations of a building at the same time as architectural design work commences. Subsurface conditions beneath a site can strongly influence fundamental decisions about a building—its location on the site, its size and shape, its weight, and the required degree of flexibility of its