they started using rebar in concrete in the mid-19th century.
they started using rebar in concrete in the mid-19th century.
when did they start using rebar in concrete?
the mid-19th century
reinforcing bars in masonry construction have been used since at least the 15th century (2,500 meters of rebar was used in the château de vincennes). during the 18th century, rebar was used to form the carcass of the leaning tower of nevyansk in russia, built on the orders of the industrialist akinfiy demidov. the cast iron used for the rebar was of high quality, and there is no corrosion on the bars to this day. the carcass of the tower was connected to its cast iron tented roof, crowned with one of the first known lightning rods. however, it was not until the mid-19th century that rebar displayed its greatest strengths with the embedding of steel bars into concrete, thus producing modern reinforced concrete. several people in europe and north america developed reinforced concrete in the 1850s. these include joseph-louis lambot of france, who built reinforced concrete boats in paris (1854) and thaddeus hyatt of the united states, who produced and tested reinforced concrete beams. joseph monier of france is one of the most notable figures for the invention and popularization of reinforced concrete. as a french gardener, monier patented reinforced concrete flower pots in 1867, before proceeding to build reinforced concrete water tanks and bridges.
rebar
rebar cages are fabricated either on or off the project site commonly with the help of hydraulic benders and shears. however, for small or custom work a tool known as a hickey, or hand rebar bender, is sufficient. the rebars are placed by steel fixers "rodbusters" or concrete reinforcing iron workers, with bar supports and concrete or plastic rebar spacers separating the rebar from the concrete formwork to establish concrete cover and ensure that proper embedment is achieved. the rebars in the cages are connected by spot welding, tying steel wire, sometimes using an electric rebar tier, or with mechanical connections. for tying epoxy coated or galvanised rebars, epoxy coated or galvanized wire is normally used, respectively.
rebar