A spasm is a sudden, involuntary contraction of a muscle, a group of muscles, or a hollow organ such as a heart, or a similarly sudden contraction of an orifice.It most commonly refers to a muscle cramp which is often accompanied by a sudden burst of pain, but is usually harmless and ceases after a few minutes. spasm is a sudden, involuntary contraction of a muscle, a group of muscles, or a hollow organ such as a heart, or a similarly sudden contraction of an orifice.
Top 10 largest Cement Producing Countries in the World. China has the first stage in the list of cement producing countries. They produce more than 2482 million tonnes. It is mainly used for construction and china is highly populated.
Besides water, concrete is the most commonly used material on earth. Cement production is responsible for about 1% of the greenhouse gases emitted in the US. More than half (60%) of the CO2 emitted during cement production is due to calcination, a chemical reaction from heating limestone. Concrete reabsorbs most of the CO2 emitted by calcination during the time it serves its useful life, and shortly after it is demolished and crushed.