No. 100 refers to cement mortar strength it is 100kg / cm2, but now all changed in MPa, and 100 corresponding to the number M10. Mix according to different raw materials, mortar use varies, in the usual 42.5 ordinary portland cement, sand with 100 (M10) mortar example: cement 305kg: sand 1.10m3: water 183kg. Mortar labels have M3, M5, M7.5, M10, M12.5, M15, M20, M25, M30, M40 are several. By zoning have masonry mortar, plastering, several unrelated seams, and labels. After the completion of cement mortar and most importantly a process, it is air-dried. It refers to air-dry for 2-3 days in the natural state. The main way to prevent the shipment of cement due to the bumps cause cracks. Since the steel tube filled with concrete, can absorb a lot of heat, so when subjected to fire string section temperature field distribution is very uneven, increasing the pillars of fire resistance, slowing the rate of temperature rise of steel columns and steel columns once yield, concrete Most can withstand axial load, to prevent structural collapse. The fire resistance of composite beam will be improved because the steel beam from the top flange temperature heat transfer to the concrete increases. The experimental statistics show: refractory three hours to reach level requirements and steel columns savings compared to a fire-resistant coating 1/3 2/3 or more, with the steel pipe diameter increases, the more paint savings. High capacity, ductility, seismic superior performance anti-corrosion steel used for: public works: for high-rise building water supply, heat supply network, water works, gas transportation, underground water and other pipelines. Oil: Oil pipeline, chemical and pharmaceutical, printing and dyeing industry, transport process piping of corrosive media. Sewage treatment: sewage discharge pipes, sewers and biological tank corrosion engineering Agriculture: irrigation pipes, deep well pipes, drains and other networks, excellent corrosion resistance of steel pipe in favor of anti-fire and anti-corrosion mortar fire Pipeline: a mixture of cement, sand and water, called cement mortar. Commonly referred to as 1: 3 cement mortar with 1 part cement and 3 parts sand with, in fact, ignoring the composition of the water, usually in the ratio of about 0.6, which should be 0.6: 1: 3 cement mortar use in building works the first is the basic and masonry wall, used as a binder massive masonry materials, such as masonry rubble, brick use cement mortar; the second is for indoor and outdoor plaster. When using the cement mortar, but also often incorporated additives such as micro-foaming agent, waterproof powder, in order to improve its workability and viscosity. Cement mortar in proportion to join stones, it becomes concrete. Cement mortar strength grade is meant by standard methods for the production and conservation of cubic specimens at the age of 28d, a value measured by Standard Test Method for Compressive Strength of the overall distribution.