Construction World August 2020

CEMENT & CONCRETE TECHNOLOGY

Waterstops vital part of COMMUNITY AND CIVIC PROJECTS

durajoint waterstops, provided by a.b.e. Construction Chemicals, part of the Chryso Southern Africa Group, have been widely used in concrete construction or expansion joints in essential community projects throughout the African sub-continent.

T he durajoint waterstop range made from specially-formulated 39& RU UXEEHU KDV EHHQ DZDUGHG OHDGLQJ RYHUVHDV FHUWLͤFDWLRQ including ASTM and CKS, and Ivor Boddington, a.b.e. Construction Chemicals Technical Manager, says the quality aspect of waterstops VKRXOG EH SDUDPRXQW LQ VHOHFWLQJ VXFK ZDWHUSURRͤQJ SURGXFWV “All too often, engineers and contractors are swayed by the price of a SURGXFW DQG GR QRW FRQVLGHU WKH SURͤOH WKLFNQHVV DQG RYHUDOO TXDOLW\ RI WKH ZDWHUVWRS WR HQVXUH WKDW WKH VSHFLͤHG SURGXFW ZLOO LQGHHG provide the required seal for major water-retaining structures.” Projects where a.b.e. durajoint waterstops were used to protect the concrete surfaces and joints of waste water treatment works include Vredenburg, Kruisfontein, and Fishwater Flats; and to contain the molten salt that drives the generators at the multi-billion rand Kathu Solar Park in the Northern Cape; as well DV IRU WKH ZDWHUSURRͤQJ RI QHZ ZDWHU UHVHUYRLUV FXUUHQWO\ XQGHU construction in various parts of Gauteng. a.b.e. durajoint protection was also used in the building of Eskom’s multi-billion rand Braamhoek Dam hydro-electric scheme and, in Malawi, for a new water treatment plant at Lilongwe, and for the upgrading

of the Blantyre Water Board reservoirs. Boddington says the durajoint waterstop range comprises four products: • GXUDMRLQW 39& ZDWHUVWRSV ZKLFK DUH ͥH[LEOH DQG HDVLO\ ZHOGHG RQ VLWH WR SURYLGH WKH SULPDU\ VHDO LQ WKH ZDWHUSURRͤQJ RI ZDWHU UHWDLQLQJ DQG RU ZDWHU H[FOXGLQJ VWUXFWXUHV 7KH\ DUH ZLGHO\ VSHFLͤHG WR SUHYHQW UHJUHVV RU LQJUHVV RI ZDWHU RU OLTXLGV WKURXJK FRQVWUXFWLRQ RU H[SDQVLRQ MRLQWV LQ ZDWHU UHWDLQLQJ structures such as dams, reservoirs, digesters, water towers, canals, basements, car parks and retaining walls. It can withstand a 10 metre head of water. • durajoint rubber waterstops, produced in straight lengths and IDFWRU\ PRXOGHG LQWHUVHFWLRQV IURP QDWXUDO UXEEHU DUH ͥH[LEOH enough to accommodate high joint movements of over 10 mm. “These durable rubber waterstops have a ‘memory’ and will UHWXUQ WR WKHLU QDWXUDO SURͤOHV DIWHU ORQJ SHULRGV RI H[WHQVLRQ GHͥHFWLRQ RU UDSLG DQG UHSHDWHG PRYHPHQW 7KH\ DUH RIWHQ applied as a grout check in concrete, double curvature, and arch GDPV DQG FDQ ZLWKVWDQG D PHWUH KHDG RI ZDWHU̹ KH H[SODLQV • durajoint SW-B, sodium bentonite (absorbent clay) waterstops seal by immediate swelling and crystallisation, and are used for cold joint sealing of in-situ concrete construction where conventional waterstops are impractical such as in restricted space or access situations. This product is effective for decades and salt-tolerant in concrete and ground water conditions. • durajoint SW-R Hydrophilic Butyl rubber waterstops are high performance synthetic elastomer strips that seal prefabricated concrete elements such as joints in tunnels and shafts, and may also be used for open joints. “The waterstops’ ‘new JHQHUDWLRQ̵ UXEEHU VHDOLQJ PDWHULDO FDQ H[SDQG E\ XS WR while still retaining stability. It is ideal for use in tunnels in SUHVVXUH FRQGLWLRQV ZLWK XS WR ͤYH EDU ZDWHU SUHVVXUHV DQG LQ FRQͤQHG DUHDV FDQ PRXOG LWVHOI WR H[HUW SUHVVXUH HYHQO\ RQ surrounding surfaces - even when these are rough with gaps of uneven size. This means a strong waterproof seal can be achieved without the need for any high compression force,” Boddington adds. ƒ

Left: An a.b.e. durajoint waterstop being inserted on site. Right: D E H ̸V GXUDMRLQW SURWHFWLRQ ZDV VSHFLͧHG IRU WKH FRQVWUXFWLRQ RI (VNRP̸V multi-billion rand Braamhoek Dam hydro-electric water scheme – one of many key national projects for which the product was used.

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CONSTRUCTION WORLD AUGUST 2020