To certain the required properties of stones, the following tests can be conducted: (i) crushing strength test (ii) water absorption test (iii) abrasion test (iv) impact test (v) acid test. (i) Crushing Strength Test: For conducting this test, specimen of size 40 × 40 × 40 mm are prepared from parent stone. Then the sides are finely dressed and placed in water for 3 days….
The following are the requirements of good building stones: (i) Strength: The stone should be able to resist the load coming on it. Ordinarily this is not of primary concern since all stones are having good strength. However in case of large structure, it may be necessary to check the strength. (ii) Durability: Stones selected…
Stone is a ‘naturally available building material’ which has been used from the early age of civilization.It is available in the form of rocks, which is cut to required size and shape and used as building block.It has been used to construct small residential buildings to large palaces and temples all over the world. Type of Stones Stones used…
Imagine a city that could devour the very pollution that it creates. Such was the scenario envisioned by scientists in the Netherlands, who have found that using specially treated pavement on city streets can cut air pollution nearly in half. The researchers from Eindhoven University of Technology installed concrete paving which included titanium dioxide –…
Lead paint without cracks, fragmentation or deterioration is not likely to be considered hazardous for human health. However, if lead paint has been used in the homes then extra care is essential to avoid unnecessary exposure to lead dust. The door frames and stair railings may have lead paint. Basics Of Lead Paint Paint is a material…
Paint removal is a technique that requires special skill to prevent damage to the surfaces from where paint is removed. The traditional methods for paint removal require a lot of skill and time. Infrared heat gun may be used for paint removal that is much more fast, reliable, and safe. Infra Red Paint Removal Techniques The infra…
Paints are used to ensure protection of the buildings from harmful weather effects, including rain, heat, and winds, and also to improve the surface finish. The useful life of structures is influenced by the application of paints that are available in several varieties of colors and textures. Fundamentals Of Paint Paint is in a liquid state and is transformed…
Autogenous healing is common in underground drainage pipes because of the presence of water on either side of the pipes. The non-moving cracks in concrete pipes are sealed by calcium carbonate crystals from carbon dioxide in air and calcium hydroxide in concrete in the process called autogenous healing. The healed cracks are impermeable and behave…
For carbon dioxide attack, carbon dioxide dissolves in water to form a weak acid called carbonic acid. It would dissolve the cement matrix. However, the amount of carbon dioxide from the atmosphere is usually not sufficient to cause harm to concrete structures until additional source of carbon dioxide is available (e.g. decaying vegetable matter). Carbonation…
Carbon dioxide and chloride present in the concrete are inert in the absence of the water and oxygen. Carbon dioxide in the pore of the concrete reacts with water to form carbonic acids which reduce the pH of the concrete. In the absence of water carbon dioxide is in active. Chloride in concrete is also…