There is a point where cement mortar and SBR slurry stop being enough. When a joint has to carry real structural load, when you need to fix a steel bracket into concrete, anchor a threaded rod that will hold weight, or bond a new section so firmly that it becomes part of the original, you need a structural epoxy adhesive. Epoxy is the strongest bond most sites will ever use, and used correctly it can be stronger than the concrete around it.
This guide explains what a structural epoxy adhesive is, the jobs it does, and how to use it, along with the Sika products Khandelwal Trading Co. stocks in Panchkula. It is written for contractors, fabricators, and site engineers across the Tricity who need a bond or an anchor they can trust with load.
What makes structural epoxy different
A structural epoxy is a two-part system, a resin and a hardener, that you mix together just before use. Once mixed, it cures by chemical reaction into an extremely strong, rigid, durable solid. That chemistry gives it a set of properties cementitious products cannot match:
- Very high bond and compressive strength, capable of carrying structural load.
- Bonds dissimilar materials, concrete to concrete, steel to concrete, and more.
- Cures without shrinkage, so the joint stays tight and gap-filling.
- Excellent chemical and water resistance, for harsh and wet environments.
- Thixotropic grades hold on vertical and overhead surfaces without sagging.
The trade-off is that epoxy is mixed in measured parts, has a limited working time once mixed, and costs more per kilogram than cement. You use it where its strength is genuinely needed, not for general patching.
The jobs structural epoxy does
Structural bonding
Sikadur-31 is a two-part, high-strength, thixotropic epoxy adhesive, the workhorse for structural bonding. It bonds concrete to concrete, steel to concrete, and a wide range of building materials, fixes plates and sections, and can seal cracks. Because it is thixotropic, it stays put on vertical and overhead joints, and it hardens without shrinkage into a very strong, chemical-resistant bond.
Bonding fresh concrete to hardened concrete
Sikadur-32 is formulated specifically as a bonding bridge between old, hardened concrete and a fresh concrete pour, so the new casting bonds structurally to the existing substrate rather than just sitting on it.
Anchoring bars and bolts
For fixing threaded rods, bolts, and reinforcement bars into drilled holes, Sika’s chemical anchoring adhesives do the job with far higher hold than a mechanical plug in many substrates. The Sika AnchorFix range covers this, including high-performance epoxy grades such as AnchorFix-3001 and AnchorFix-3030 for anchoring rods and rebar in cracked and uncracked, dry or damp concrete, and AnchorFix-2 for threaded bars in uncracked concrete. Anchoring with adhesive puts no expansion force on the concrete, so it can be used close to edges where a wedge anchor would crack the substrate.
Sealing and injecting cracks
For structural cracks, low-viscosity epoxy injection resins such as Sikadur-52 are injected under pressure to penetrate and re-bond fine cracks, restoring monolithic strength rather than just filling the surface.
Strengthening existing structures
Where a member needs more capacity, Sika’s carbon-fibre strengthening systems, Sika CarboDur plates and SikaWrap fabrics, are bonded to concrete with structural epoxy to add load capacity without heavy, bulky sections. This is specialist work, but it shows how far epoxy bonding extends beyond a simple repair.
How to use structural epoxy, the basics
Exact mix ratios, pot life, and cure times are printed on each product data sheet and must be followed, because epoxy is unforgiving of guesswork. The general method is consistent.
For bonding
- Prepare the surface. Concrete must be sound, clean, and free of dust, oil, grease, and laitance. Steel should be clean and free of rust and scale.
- Mix the two parts fully. Combine resin and hardener in the correct ratio and mix to a uniform, streak-free colour. Under-mixing leaves soft spots that never cure.
- Apply within the pot life. Spread the epoxy and bring the parts together before the working time runs out. Mixed epoxy generates heat and stiffens as it goes off.
- Hold in position. Clamp or support the joint until the epoxy has cured enough to hold on its own.
For anchoring
- Drill and clean the hole to the specified diameter and depth, then remove all dust with a brush and blower. A dirty hole is the most common cause of a weak anchor.
- Inject the adhesive from the base of the hole outward, filling to avoid trapping air.
- Insert the rod or bar with a twisting motion so the adhesive coats it fully.
- Leave undisturbed to cure for the full time before loading.
Epoxy or SBR: which bond do you need
The choice is about load. An SBR bonding agent improves the grip between cement-based materials and is perfect for plaster, screeds, and general patch repairs. A structural epoxy carries real load and bonds dissimilar materials, which an SBR cannot do. As a rule: for a cementitious topping bonding to concrete, use SBR; for a load-bearing connection or an anchor, use epoxy.
Our companion guide covers the cementitious side in full: SBR bonding agents for joining new concrete to old. For how bonding and anchoring fit into the complete repair system, see our pillar guide on concrete repair and surface strengthening with Sika.
Beyond concrete: stone and marble
Epoxy bonding is not limited to concrete and steel. In stone and marble work, specialised epoxy systems are used to bond slabs, fill and colour-match cracks, and make invisible repairs on premium surfaces. If your work runs into natural stone, our AKEMI stone and marble care guide covers the dedicated AKEPOX epoxy range and where it fits, from mitre joints on countertops to crack repair on polished marble.
Buying structural epoxy and anchors in Panchkula
Khandelwal Trading Co. stocks Sika structural epoxies and anchoring adhesives along with the wider repair range, so you can specify a bond or an anchor and pick up everything the job needs in one place. Tricity contractors treat us as the “Google shop for the construction industry,” and for structural work that means getting the right grade for the load, not just any epoxy. If a specific grade or cartridge size is not on the shelf, we can usually source it. Browse the range on our construction chemicals and adhesives page.
Whether you are anchoring rebar for a column extension or bonding a steel plate to a beam, come in, call, or message us and we will help you pick the right product, grade, and quantity.
Frequently asked questions
What is a structural epoxy adhesive used for?
For load-bearing bonds and anchors: bonding concrete to concrete or steel to concrete, fixing plates and sections, anchoring threaded rods and rebar, sealing structural cracks, and bonding carbon-fibre strengthening systems. It is used wherever a cementitious bond is not strong enough to carry load.
Is epoxy stronger than concrete?
A properly mixed and applied structural epoxy typically develops a bond stronger than the concrete itself, which is why a correctly made epoxy joint often fails in the surrounding concrete rather than at the glue line. That strength depends entirely on clean preparation and correct mixing.
Can I anchor bolts into concrete with epoxy?
Yes. Chemical anchoring adhesives such as the Sika AnchorFix range are made for exactly this, fixing threaded rods, bolts, and rebar into drilled holes. They anchor without expansion force, so they can be used closer to edges than mechanical anchors. Clean the drilled hole thoroughly for full strength.
Why does my epoxy stay soft or sticky?
Almost always because the two parts were not mixed in the right ratio or not mixed thoroughly. Epoxy must be combined in the correct proportion and stirred to a uniform colour, then used within its pot life. Follow the data sheet exactly.
When should I use SBR instead of epoxy?
Use an SBR bonding agent for cement-based work such as plaster, screeds, and general patch repairs, where the bond does not carry structural load. Save epoxy for load-bearing connections and anchoring, where its higher strength is genuinely needed.
Get the right epoxy or anchor for your job
Tell us the connection, what is bonding to what and how much load it carries, and we will match it to the correct Sika structural epoxy or anchoring adhesive, grade, and quantity. Visit Khandelwal Trading Co. at Shop No. 4, Street No. 2, Maheshpur, Sector 21, Budanpur, Panchkula, call us on 94175 65977, or message us on WhatsApp. Trade enquiries are welcome through our get a quote page.
