Search results
Results from the WOW.Com Content Network
Concrete sealers are applied to concrete to protect it from surface damage, corrosion, and staining. They either block the pores in the concrete to reduce absorption of water and salts or form an impermeable layer which prevents such materials from passing.
Sealant is a substance used to block the passage of fluids through openings in materials, [1] a type of mechanical seal. In building construction sealant is sometimes synonymous with caulk (especially if acrylic latex or polyurethane based) [ 2 ] and also serve the purposes of blocking dust, sound and heat transmission.
A common type of insulated slab is the beam and block system (mentioned above) which is modified by replacing concrete blocks with expanded polystyrene blocks. [11] This not only allows for better insulation but decreases the weight of slab which has a positive effect on load bearing walls and foundations. Formwork set for concrete pour.
Oxidation of pyrite in clay formations in contact with concrete – this produces sulfuric acid which reacts with concrete. Bacterial activity in sewers – anaerobic sulfate reduction at work in the organic-rich sludges accumulated under water in the conduits produces hydrogen sulfide gas (H 2 S).
The steel shuttering pinches the top surface of a concrete slab due to the weight of the next slab being constructed. Concrete slabs, block walls and pipelines are susceptible to cracking during ground settlement, seismic tremors or other sources of vibration, and also from expansion and contraction during adverse temperature changes.
Beam and block is a construction method to support flooring, especially for ground floors as well as multi story buildings. [1] It is made of cast concrete , one piece of which is a prestressed concrete beam , which can be an inverted T-shaped beam, or lintel, the other piece being a simple rectangular block. [ 1 ]
Penetrating sealers often require the use of special cleaners which both clean and top up the repellent ingredient left on the stone surface. These sealers are often breathable to a certain degree, but do not penetrate deeply enough (generally less than 1mm) to be effective against salt attack, such as efflorescence and spalling.
A coolant is a substance, typically liquid, that is used to reduce or regulate the temperature of a system. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, chemically inert and neither causes nor promotes corrosion of the cooling system. Some applications also require the coolant to be an electrical insulator.