{"product_id":"西卡永聯結-sika-ronacrete-unicell-primer","title":"Sika Ronacrete Unicell Primer","description":"\u003cdiv class=\"tldr-box\" style=\"background:#f0f4f8;border-left:4px solid #2c5282;padding:16px;margin-bottom:24px\"\u003e\n\u003cstrong\u003eSummary:\u003c\/strong\u003e\u003cp\u003eUnicell Primer is a liquid bonding and priming aid by Sika Ronacrete. When mixed with OPC, it forms a brushable slurry that passivates exposed steel reinforcement and enhances mortar-to-concrete bond strength. Coverage 4-8 m²\/litre, 9-month shelf life.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eUnicell Primer — Rebar Primer \u0026amp; Bonding Aid\u003c\/h2\u003e\n\u003cp\u003eUnicell Primer is a liquid bonding and priming aid that requires mixing with ordinary Portland cement (OPC) to form a brushable slurry. Applied to exposed steel reinforcement, it forms a tough flexible passivating layer against damaging ions and oxidation. Applied to concrete substrates, it provides enhanced bonding and a barrier to water and ion ingress. Water-based formula with low VOC (\u003c10g\/L), economic and easy to use. Designed specifically for the Unicell range but also compatible with most cementitious mortars, renders, concretes, and screeds.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eSteel passivation:\u003c\/strong\u003e Forms an anti-corrosion barrier on exposed reinforcement\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eEnhanced bonding:\u003c\/strong\u003e Significantly improves bond between repair mortar and substrate\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eWaterproofing barrier:\u003c\/strong\u003e Resists water and harmful ion penetration\u003c\/li\u003e\n\u003cli\u003eWater-based, low VOC (\u003c10g\/L)\u003c\/li\u003e\n\u003cli\u003eSimply mix with cement for easy application\u003c\/li\u003e\n\u003cli\u003eEconomic\u003c\/li\u003e\n\u003cli\u003eDesigned for the Unicell range, also compatible with other cementitious mortars\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eUnicell Concrete Repair System\u003c\/h2\u003e\n\u003cp\u003eUnicell Primer is the first step in the Sika Ronacrete concrete repair system:\u003c\/p\u003e\n\u003col\u003e\n\u003cli\u003e\u003cstrong\u003eStep 1: Unicell Primer\u003c\/strong\u003e — Rebar passivation + substrate bonding coat\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eStep 2: Unicell 25 or Unicell 40\u003c\/strong\u003e — Repair mortar to fill spalled areas\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eStep 3: Finishing\u003c\/strong\u003e — Render or paint\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTypical Applications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eSteel protection in reinforced concrete\u003c\/li\u003e\n\u003cli\u003eBonding coat before concrete repair\u003c\/li\u003e\n\u003cli\u003eThin\/thick section bonding for mortars\u003c\/li\u003e\n\u003cli\u003ePrimer for screeds and renders\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy Choose Unicell Primer?\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eDual function:\u003c\/strong\u003e Bonding primer and rebar passivation in one product\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eHigh bond strength:\u003c\/strong\u003e With Unicell 40, achieves 2.7 MPa at 7 days, exceeding HKHA requirements\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eLow VOC:\u003c\/strong\u003e Water-based formula with VOC below 10g\/L\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eCost effective:\u003c\/strong\u003e Coverage rate of 4-8 m²\/litre\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePackaging \u0026amp; Consumption\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\u003cth\u003eItem\u003c\/th\u003e\u003cth\u003eSpecification\u003c\/th\u003e\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\u003ctd\u003ePackaging\u003c\/td\u003e\u003ctd\u003e5 litre drum \/ 30 litre drum\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eAppearance\u003c\/td\u003e\u003ctd\u003eMilky white liquid (blue after mixing with OPC)\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eCoverage\u003c\/td\u003e\u003ctd\u003e4-8 m²\/litre\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eMixing Ratio (by volume)\u003c\/td\u003e\u003ctd\u003e1 part Primer : 1.5 parts OPC\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eMixing Ratio (by weight)\u003c\/td\u003e\u003ctd\u003e1 part Primer : 2 parts OPC\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eShelf Life\u003c\/td\u003e\u003ctd\u003e9 months from date of production\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eStorage\u003c\/td\u003e\u003ctd\u003eUnopened original sealed packaging, +5°C to +35°C, protect from sunlight and frost\u003c\/td\u003e\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\u003cth\u003eProperty\u003c\/th\u003e\u003cth\u003e7 Days\u003c\/th\u003e\u003cth\u003e28 Days\u003c\/th\u003e\u003cth\u003eHKHA Requirement\u003c\/th\u003e\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\u003ctd\u003eBond Strength (with Unicell 25)\u003c\/td\u003e\u003ctd\u003e2.2 MPa\u003c\/td\u003e\u003ctd\u003e3.0 MPa\u003c\/td\u003e\u003ctd\u003eMin 1.5 MPa at 7 days (Class 25)\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eBond Strength (with Unicell 40)\u003c\/td\u003e\u003ctd\u003e2.7 MPa\u003c\/td\u003e\u003ctd\u003e3.5 MPa\u003c\/td\u003e\u003ctd\u003eMin 2.0 MPa at 7 days (Class 40)\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd\u003eBond Strength (with Unicell WF)\u003c\/td\u003e\u003ctd\u003e2.5 MPa\u003c\/td\u003e\u003ctd\u003e3.0 MPa\u003c\/td\u003e\u003ctd\u003eN\/A\u003c\/td\u003e\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003eTest Method: TM4\u003c\/p\u003e\n\n\u003ch2\u003eImportant Notes\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eAmbient temperature must be above 5°C\u003c\/li\u003e\n\u003cli\u003eRemove all defective concrete to a sound substrate; loose rust and scale must be removed\u003c\/li\u003e\n\u003cli\u003eCut around repair perimeter to minimum 6 mm depth with angle grinder to avoid feather edges\u003c\/li\u003e\n\u003cli\u003eMix with cement using a slow speed drill (approx. 500 rpm), adding cement slowly\u003c\/li\u003e\n\u003cli\u003eAllow the rebar passivation coat to dry, then apply a second coat of primer to reinforcement and concrete as the bonding coat\u003c\/li\u003e\n\u003cli\u003eApply repair mortar (Unicell 25\/40\/WF) while the bonding coat is still wet\/tacky\u003c\/li\u003e\n\u003cli\u003eIf the primer dries completely, it must be reapplied\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eUnicell Primer vs Mapefer vs Fosroc Primer Comparison\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eProduct\u003c\/th\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003cth\u003eUse\u003c\/th\u003e\n\u003cth\u003eFeatures\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eUnicell Primer\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eSika Ronacrete\u003c\/td\u003e\n\u003ctd\u003eRebar primer + bonding\u003c\/td\u003e\n\u003ctd\u003eDual function: bonding primer + passivation, pairs with Unicell mortars\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMapefer 1K\u003c\/td\u003e\n\u003ctd\u003eMapei\u003c\/td\u003e\n\u003ctd\u003eRebar anti-corrosion\u003c\/td\u003e\n\u003ctd\u003eDedicated anti-corrosion, pairs with Planitop mortars\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFosroc Primer 7\u003c\/td\u003e\n\u003ctd\u003eFosroc\u003c\/td\u003e\n\u003ctd\u003eEpoxy primer\u003c\/td\u003e\n\u003ctd\u003ePairs with Renderoc repair range\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptimix PE\u003c\/td\u003e\n\u003ctd\u003eOptimix\u003c\/td\u003e\n\u003ctd\u003eInterface agent + anti-corrosion\u003c\/td\u003e\n\u003ctd\u003eSBR polymer, pairs with RM series\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eFAQ\u003c\/h2\u003e\n\u003ch3\u003eWhat is the difference between Unicell Primer and Mapefer?\u003c\/h3\u003e\n\u003cp\u003eBoth serve similar functions but differ in formulation. Unicell Primer is a liquid polymer that must be mixed with cement (1:1.5 by volume or 1:2 by weight), providing both bonding and rebar passivation. Mapefer 1K is a single-component cementitious anti-corrosion mortar applied directly. Choose based on your repair mortar brand — Unicell Primer with Unicell mortars, Mapefer with Mapei mortars.\u003c\/p\u003e\n\n\u003ch3\u003eIs a primer necessary for concrete repair?\u003c\/h3\u003e\n\u003cp\u003eIf exposed reinforcement is present, Unicell Primer is strongly recommended for steel passivation. For surface-only repairs without exposed rebar, the primer still significantly improves bond strength between repair mortar and substrate, reducing the risk of future delamination.\u003c\/p\u003e\n\n\u003ch3\u003eWhat is the coverage rate of Unicell Primer?\u003c\/h3\u003e\n\u003cp\u003eWhen mixed with OPC cement, coverage is approximately 4-8 m² per litre, depending on surface roughness and porosity of the substrate.\u003c\/p\u003e","brand":"Sika Ronacrete 西卡永聯結","offers":[{"title":"Default Title","offer_id":43686304252054,"sku":"","price":1.0,"currency_code":"HKD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0594\/9027\/1382\/files\/hk-02-en-HK-Unicell-Primer-01-1x1-00590065.webp?v=1716652991","url":"https:\/\/wahhingwp.com\/en\/products\/%e8%a5%bf%e5%8d%a1%e6%b0%b8%e8%81%af%e7%b5%90-sika-ronacrete-unicell-primer","provider":"華興建築防水材料有限公司","version":"1.0","type":"link"}