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This paper aims to assess the effects of chemically accelerated leaching on the physical and mechanical properties of aerial lime–cement mortars (LCMs).

Two aerial LCMs, differencing mainly in their calcium hydroxide content, were degraded by the use of an ammonium nitrate solution as a leaching agent. The leaching effects were studied by evaluating the rate of change in physical (sorptivity and mass loss) and mechanical (flexural and compressive strength) characteristics of aerial LCMs. To quantify the evolution and kinetics of degradation, the leached depth was then characterized at different levels of degradation by means of a phenolphthalein solution.

The experimental results showed that the dissolution of binder decreases the mass, alkalinity and strength of aerial LCMs but increases their sorptivity. A linear relationship was derived by plotting the values of leached depth against the square root of immersion time in an aggressive solution. It was found that the leached depth followed diffusion-controlled kinetics.

It was found that the global loss of compressive strength of aerial LCMs because of complete dissolution of calcium hydroxide can reach up to 80 per cent.

Discusses the properties of concrete and the process of carbonation which can lead to corrosion and its ultimate destruction. Outlines the conditions which lead to carbonation, detailing design faults which facilitate the process, and suggests preventatives which can protect the surface. Examines the results of carbonation, the forming of distressed concrete and mentions tests which can be performed to check the health of the structure. Assesses the impact of additional factors leading to corrosion and offers advice on remedial actions.

About 26,000 Airey Houses were erected during the post war years (1946–55) as part of the house building programme of that period. The Airey House is essentially a prefabricated concrete structure which was erected on site to form a box. This box was erected upon a concrete raft which acted as the foundation and floor of the dwelling. The basic box was formed from several framed ‘goal posts’ to which thin concrete cladding panels were fastened to the upright columns by copper wire. The vertical loading from the first floor and roof is taken on the vertical columns but may also be shared with the concrete cladding panels (see Figure 1).

In this paper, wear of the cylinder is taken to mean not only wear of the liner but of the piston ring assembly also, since usually, though not always, the wear of the one is closely related to that of the other. The wear process may be corrosive, abrasive or frictional, and it is likely that all three processes occur together to varying extents, depending on such factors as engine design and operating conditions.

Industrial processes in everyday life need to take into consideration environmental safety. This is the major goal of today's scientific research. Textile research is no exception. This paper illustrates a green process in which indigo is converted into its water-soluble leuco form by using a reducing agent that is ecologically friendly: 3-hydroxybutanone (C4H8O2). The effect of alkalinity and reducing temperature on the reducing power of C4H8O2 has been evaluated in the absence and presence of indigo. The dyeing quality of the modified cotton resultant of the exhaust process is studied. Cotton modification is carried out by using Denitex BC 200% in order to improve the quality of the exhaustion dyeing process. Modified cotton fibres are characterized through a morphology analysis (by using a SEM), Fourier transform infrared spectroscopy and X-ray diffraction analysis. The performances of the indigo dyeing process are evaluated by measuring the redox potentials generated in the medium with and without indigo, dyeing bath exhaustion (E(%)), and colour yield (K/S) of the coloured cotton at 660 nm, brightness index (B(%)) and dyeing fastness of both the untreated and modified cotton fabrics.

Boiler water test methods. A comprehensive range of easy‐to‐use boiler water tests have been developed by Wilkinson & Simpson Ltd, Palintest House, 57 Queensway, Team Valley Estate, Gateshead, Tyne & Wear NE11 0NS. These are designed to provide plant managers with an accurate means of monitoring all aspects of water quality which affect boiler operation. Many modern boiler designs are very sensitive to water quality. Failure to control features such as alkalinity, hardness and treatment chemical concentrations can seriously affect boiler efficiency, energy consumption, maintenance and operating costs.

The purpose of this research is to determine the major environmental impacts and, especially, to evaluate the geochemical characteristics of water of the lakes formed in abandoned quarries of ornamental rock of the Campo Belo Metamorphic Complex.

To do so, 12 quarries were chosen to be studied. They were mapped in a detail scale and their rocks were described and sampled for petrography analysis. Whenever present, the lakes were evaluated too. In situ measurements included pH, Eh, conductivity, resistivity, total dissolved solids and temperature. Water samples were collected to determine alkalinity, sulfates, chlorates, turbidity, suspended sediments and the concentrations of major and trace elements using the ICP‐OES.

Abandoned open‐pit mining operations have resulted in the creation of numerous pit lakes. About 90 per cent of the quarries visited and studied were abandoned or interdicted by environmental organs, what will probably lead to its subsequent abandonment. The quarries Borges and Gêmeos were two quarries of the abandoned quarries in the region, which has a lake formed in its trench. Gêmeos and Borges pit lakes analytical data shows clear correlation between the chemical compositions of the solute and the geological characteristics of the quarries. In spite of the differences found, the results showed a relatively quality water according to Brazilian legislation control values.

This was the first study done of pit lakes formed in abandoned ornamental rock quarries of Campo Belo Metamorphic Complex/Minas Gerais – Brazil. This research provides a better understanding of the gneisses pit lakes hydrogeochemistry, a subject neglected in scientific literature.

BUILDING WITH ALUMINIUM. For over 60 years satisfactory service has been achieved in the building industry with aluminium components. Success has been apparent when the correct alloy has been correctly applied. However, examples of corrosion failure generally attract more attention than the smooth success stories. Such an example is embodied in a circular sent out last month by the Ministry of Housing and Local Government to local authorities concerning corrosion in certain types of aluminium bungalows. The circular follows an investigation by the Ministry and the Building Research Station.

Steel reinforcement embedded in concrete is normally protected from corrosion by the formation of a thin passive surface film in the highly alkaline environment provided by the cement paste and pore solution surrounding the steel. Atmospheric carbon dioxide reacts with the alkaline cement paste reducing the level of alkalinity, a process known as carbonation. Steel in carbonated concrete is no longer protected and in the presence of moisture and oxygen can corrode freely. Alternatively, the presence of sufficient quantities of chloride ions at the surface of the steel can cause local depassivation of the reinforcement resulting in pitting corrosion. Chloride ions may be present as a result of admixtures in the original mix or permeation into the concrete from external sources, such as road de‐icing salts or sea spray.

THE FOLLOWING is a condensed version of a paper and the ensuing discussion that was presented to the American Society of Mechanical Engineers at their Diesel & Gas Engine Power Conference at Dallas, Texas earlier this year.