M9212 - Manufacture of concrete blocks, brick, artificial stone

Operational Details
Concrete manufacturers in this industry produce sidewalk and patio blocks, parking curbs, building blocks, weights, pump bases, etc. The process involves using forms that are constructed to hold the poured concrete. The mold or frame may have reinforcing steel and wire embedded in it to add strength. Concrete is mixed, using a portable mixer, using various grades of concrete powder. Concrete finishing hand tools are also used. Finishing the concrete basically involves removing the products from the forms or molds, and using a grinder to remove imperfections in the surface of the concrete. Patterns may be etched into the concrete by using a broom or sharp object, as in the case with patio or sidewalk blocks.

Bricks are manufactured using clay and fly ash (a by-product of coal). The mixture is mixed dry in a large vat or tank. Additives such as hardeners and coloured dyes may are also included. Water is slowly added to the mixture until the desired consistency has been achieved. The mixture is extruded through a die in the form of a rectangular brick. The bricks are placed onto trays and conveyed to a kiln where they are baked. The bricks are cured, cooled and pelletized for market.

Artificial marble and stone manufacturing combines polyester resin and dolomite dust in a mixer or vat. A colouring agent is added and a catalyst creates exothemic heat needed to bond the mixture. Once hardened, the product is placed on curing racks to set. The products once cured, are polished. The process might also involve mixing a light aggregate concrete with a colouring agent, pouring the mixture into molds, and drying it in an oven. Applications for these products include: counter tops, sinks, shower stalls, hot tubs, facades for fireplaces, plant holders etc.

SIC Codes
000000603 - Mfg. concrete blocks, brick, artificial stone