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Dust-producing surfaces cover one-third of the global land area. These are made up of hyper-arid regions like the Sahara, which covers 0.9 billion hectares, and drylands, which occupy 5.2 billion hectares. [5] Dust in the atmosphere is produced by saltation and abrasive sandblasting of sand-sized grains, and it is transported through the ...
The composition of PM generated from cutting or mixing concrete made with Portland Cement would be different from those generated from cutting or mixing concrete made with different types of slag (e.g. GGBFS, EAF slag [171]), fly ash or even EAF dust (EAFD), [172] while EFAD, slag and fly ash are likely to be more toxic as they contain heavy ...
The Philippines is projected to be one of the most vulnerable countries to the impacts of climate change, [5] which would exacerbate weather extremes. As the Philippines lies on the Pacific Ring of Fire, it is prone to natural disasters, like earthquakes, typhoons, and volcanic eruptions.
The formation of fissures in the concrete cover above the reinforcement bars represents a preferential pathway for the ingress of water and aggressive agents such as CO 2 (lowering of pH around the rebar) and chloride anions (pitting corrosion) into concrete. The physical formation of cracks therefore favors the chemical degradation of concrete ...
Dust from surfaces such as floors, beds, or furniture is often collected to assess health effects from exposure in epidemiology studies. Researchers of indoor mold also use a long-term settled dust collection system where a dust cloth or a petri dish is left out in the environment for a set period of time, sometimes weeks. [18]
These include emissions of airborne pollution in the form of dust, gases, noise and vibration when operating machinery and during blasting in quarries, and damage to countryside from quarrying. Equipment to reduce dust emissions during quarrying and manufacture of cement is widely used, and equipment to trap and separate exhaust gases are ...
Concrete is used to create hard surfaces that contribute to surface runoff, which can cause heavy soil erosion, water pollution, and flooding, but conversely can be used to divert, dam, and control flooding. Concrete dust released by building demolition and natural disasters can be a major source of dangerous air pollution.
The required concrete cover depends on several factors, including the environmental conditions to which the structure will be exposed, the size of the reinforcing steel, the concrete strength, and the type of structure being constructed. Generally, larger diameter reinforcement bars require more concrete cover than smaller ones. In most cases ...