Construction World July 2021

ADMI XTURES

AVOID DELAYS IN CONCRETE FINISHING THIS WINTER

A s winter approaches, the colder ambient temperatures can cause delays in concrete strength development as wel l as f inishing aspects. This is a real headache for contractors and precast product ion plants, but the chal lenge can be easi ly overcome using CHRYSO’s winter accelerator range of admixtures. Accelerators are normal ly categorised as chloride and non-chloride based. A popular chloride-based accelerator commonly used by many dr y precast operat ions is CHRYSO® Xel C205. This product , based on calcium chloride, is an accelerat ing admixture which enhances the early stages of cement hydrat ion which in turn enhances rapid st i f fening and hardening of the concrete mix. The resul t is that f inal f inishing or mould stripping can begin at an earl ier age wi thout damaging the concrete sur face increasing product ivi ty. In the winter months, CHRYSO® Xel C205 assists in overcoming delays in concrete f inishing caused by cold weather. Suppl ied as a clear solut ion, i t instant ly disperses in water. I t can be used in appl icat ions that do not contain embedded metal , and in foamed mortar systems. CHRYSO® Xel C205 is compat ible wi th other CHRYSO® admixtures used in the same concrete mix. I t can also be used wi th al l types of ordinar y Port land cements and cement replacement materials such as

pulverised f ly ash (PFA) , ground granulated blast-furnace slag (GGBFS) and si l ica fume. CHRYSO® Xel C205 is avai lable in drum or bulk supply. For steel -reinforced concrete, the ideal solut ion is the non-chloride-based accelerat ing admixture CHRYSO® Xel 650. This can be used in al l types of cement , and appl icat ions include shuttered concrete, pre-stressed concrete, precast elements and readymix concrete. The CHRYSO® Xel 650 product helps the f i rst react ions of cement hydrat ion, especial ly at low temperatures. This signi f icant ly reduces sett ing t ime and improves early compressive strength. Packaging opt ions include 25 l i tre jerr y cans, 200 l i tre drums, 1000 l i tre f low bins and bulk del iver y. CHRYSO Xel 680 EMx is speci f ical ly used in highly extended cements. I t al lows for product ivi ty gains through pouring /stripping cycle t ime reduct ion. Moreover, i t al lows the t ime requi red and temperature of steam curing to be opt imised. Customers have access to CHRYSO’s technical advisor y ser vice for on-si te assistance and advice on admixture select ion, evaluat ion trials and dispensing equipment . Technical data and guidance can also be provided for admixtures and other products for use wi th f resh and hardened concrete. 

28 CONSTRUCTION WORLD JULY 2021