Construction World January 2018

PRODUCTS & SERVICES

Products for new landmark apartment block Chryso Eastern Africa is supplying a vital admixture for the concrete mix used for the construction of Nova Apartments, a new R180-million luxury apartment block in Nairobi, by the main contractor, Aggregate Construction.

Trevor Sawyer, Country Manager for Chryso Eastern Africa, says waterproofing products from a.b.e. Construction Chemicals – part of the Chryso SA Group – will also be used for the construction of the new landmark building in Muthangari Drive in West- lands, Nairobi. Chryso Eastern Africa is supplying a total of about 60 000 litres of CHRYSO Fluid L admixture to Aggregate Construction for the concrete required to build the multi-storey apartment block, scheduled for completion in October next year. Sawyer and Aggregate Construction’s Paresh Hirani worked in close collaboration to optimise the content and performance of the concrete mix for the project which was started in August last year. Sawyer was on site right from the first cast and Chryso Eastern Africa also supplied the main contractor with a Chryso dosing system. CHRYSO Fluid L offers several benefits to a concrete mix. Included are: • Substantially reducing the water content without negatively affecting the mix’s consistency; and • Significantly increasing the slump/flow of the concrete mix and its workability. CHRYSO Fluid L is compatible with all types

of cement on the Kenyan market, including the main stream Pozzolanic cements. The technical representative who is assisting Mau West Ltd for the waterproofing part of the project is Geoff Dagger, a.b.e. Technical Sales Representative at Chryso Eastern Africa. For the waterproofing of the swimming pool, podium, balconies and bathrooms, a.b.e. duraflex with ecofelt reinforcement to cover a total area of about 5 500 m 2 will be supplied to the specialist waterproofing contractors, Mau West Ltd. Both the main contractor and specialist waterproofers are leading Nairobi-based companies. Dagger says a.b.e.’s duraflex is a ready- to-use flexible slurry based on a special synthetic resin dispersion and a blend of selected cements, mixed with carefully selected graded aggregates. duraflex is non- toxic, self-curing, and effective on both the negative or positive side. The product has high bonding strength, and offers strong resistance to abrasion as well as chloride ion penetration. Dagger says the ecofelt reinforcement will maximise duraflex’s performance because ecofelt has internationally proved to be one of the best saturation membranes

A computerised impression of the impressive new Nova Apartments in Nairobi.

in waterproofing. “ecofelt has a highly porous fibre structure, manufactured by needle-punching the fibres to form a uniformly structured sheet,” he explained. The architects for Nova Apartments are Beglin Woods Architects Kenya, which have already won an Architectural Association of Kenya (AAK) 'Best Concept' award for the luxury residential apartments and penthouses of the spectacular new development. The Beglin Woods acclaimed design for the 17 storey Nova Apartments include an indoor/outdoor swimming pool, spa, gym, cinema, convenience store and expansive open grassed area with water features and jogging track. 

Channel lining With a proven track record exceeding 35 years, a Kaytech manufactured geocell recently saved a large retaining wall from possible catastrophic failure. The wall was built by Edilcon Construction to increase the despatch area for the Makro Store in Germiston, Gauteng.

construction while further uses include load support applications to prevent shearing and lateral movement of the infill material and as an erosion control formwork where cells are soil-filled for vegetated embankments. Bidim ® , a continuous filament, nonwoven, needlepunched geotextile, is manufactured at Kaytech’s ISO 9001 registered facility where discarded plastic cooldrink bottles are processed to create high-grade polyester. The needlepunching process provides several advantages including appreciable thickness, high porosity and a high drainage capacity. Installed directly over the soil and beneath the Multi-Cell, bidim in this project will have a dual function, that of drainage and separation. Since the contractor had no previous experience with Multi-Cell, Kaytech gladly provided on-site installation training. Upon arrival on site, Winnie Botha, a Kaytech technical sales representative, discovered neatly completed earthworks including tuck-in trenches on both sides while the layer of bidim A2 was already installed. By receiving appropriate training, the contractor was able to overcome initial installation challenges and rapidly progressed to installing 50 metres of Multi-Cell per day. Using binding wire, Multi-Cell (1 500 m 2 ) was pegged down every two metres to maintain intimate contact with the bidim A2 and soil below. Once installed the Multi-Cell layer was ready for concrete infill. With tried and tested Multi-Cell and world-renowned bidim meeting the highest civil engineering specifications, there is no doubt that drainage above the retaining wall will be effectively controlled far into the foreseeable future. 

Prior to the summer rainfall season, L & S Consulting Engineers became concerned that surface drains installed above the soil retaining wall, were possibly inadequate and could lead to excess water permeating the backfill. Instead of designing a costly steel-reinforced concrete channel to solve the problem, engineers specified Kaytech’s Multi-Cell (100 mm) and bidim A2, an economical and highly effective system to line the v-shaped surface drain. Multi-Cell is a honeycombed structure manufactured from strips of coated slit

film woven polypropylene tape stitched alternatively together to form three-dimensional diamond-shaped cells with high tensile strength and seam strength. Multi-Cell is used as an in-situ shuttering to cast continuous interlocking concrete paving for canal or road

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CONSTRUCTION WORLD JANUARY 2018