Concrete pavement jointing and curing: the rigid slab done right

Concrete pavement, jointing, and curing in one picture

Concrete pavement is a rigid slab of portland cement concrete that carries traffic by spreading the wheel load over a wide area through the stiffness of the slab itself. Two operations decide whether it lasts twenty years or cracks up in two: jointing and curing. Jointing puts the crack where you want it, because concrete is going to crack. Curing keeps the water in the slab long enough for the paste to gain strength, because a pavement has more surface exposed per unit of volume than almost anything else you pour.

Get either one wrong and the slab tells on you fast. Saw the joints too late and the slab cracks at random, ignoring every line you planned. Skip or shortchange the cure and the surface dusts, scales, and crazes, and the top quarter inch never reaches the strength the mix was paid for. Neither failure waits for the warranty to run out.

This guide walks the chain from the section under the slab to the day you open it to traffic. The same principles cover a county road, a big-box parking lot, a truck apron, and a data center generator pad. The loads and the spec numbers move, the physics does not.

Concrete vs asphalt pavement: what is the difference?

Concrete is a rigid pavement and asphalt is a flexible pavement, and the difference is how each one moves the wheel load down to the dirt. The concrete slab is stiff. It picks the load up and bends across a wide footprint like a beam, so the pressure that actually reaches the subgrade is low and spread out. Flexible asphalt does not bend as a beam. It passes the load down through the layers in a cone, so the stress on the subgrade right under the tire is higher and the structure leans harder on the strength of the base and subgrade.

That one difference sets where each pavement wins. Concrete pays off under heavy, slow, and turning loads, where asphalt ruts and shoves: bus pads, truck aprons, intersections, dock approaches, container yards. It holds up to fuel and oil and heat that soften asphalt, which is why fueling lanes and aircraft aprons go concrete. And it lasts. A well built concrete pavement runs decades with little more than joint maintenance, where asphalt is on a resurfacing cycle.

Asphalt wins on first cost, on speed, and on the ability to open to traffic the same day, and it is far easier to patch and resurface. The asphalt mill and overlay guide covers that side of the trade. When the question is which pavement to build, it comes down to the load, the life you need, and the budget, and the structural design from the project engineer settles it, not a rule of thumb.

The pavement section: subgrade, subbase, slab

A concrete pavement is a section, not just a slab, and it fails from the bottom up as often as the top down. The subgrade is the prepared native soil, the foundation everything else sits on. The subbase is an engineered layer of granular or stabilized material on top of it. The PCC slab rides on the subbase. The slab is stiff enough that it does not need the structural support a flexible pavement does, but it needs one thing absolutely: uniform support.

Uniform is the word that matters. A rigid slab spans soft spots, so a slab on support that is stiff in one place and soft in the next bends to bridge the gap and cracks from the bending. The job of the subgrade and subbase is not raw strength so much as consistency, drainage, and no pumping. The same uniform-support principle runs through the pavement condition assessment guide, because the base failures it diagnoses start here.

Water is the enemy of that uniform support. Let water sit under the slab and the truck traffic pumps it out through the joints, carrying fines with it, and now there is a void under the slab edge. The slab loses its support at the joint, the panels rock, and you get faulting and corner breaks. A free-draining, non-erodible subbase and positive drainage are what keep the support uniform over time. Pour a good slab on a base that pumps and you have built in the failure before the concrete ever sets.

Why does concrete pavement have to be jointed?

Concrete shrinks as it cures and dries, and it keeps moving with temperature for the rest of its life. The subbase and the slab's own weight restrain that movement, and restrained shrinkage builds tensile stress in concrete, which is weak in tension. When the stress beats the tensile strength, the slab cracks. There is no mix and no admixture that stops this. You do not prevent the crack. You decide where it happens.

That is the whole point of jointing. A joint is a deliberate plane of weakness that pulls the crack down to a line you chose, straight and at the bottom of a sawed groove, instead of a ragged crack wandering across the panel where it wants. Cut the joints right and the pavement cracks under them, out of sight and under control. Cut them wrong, too shallow, too late, or too far apart, and the slab relieves the stress on its own terms with a random crack you now own for the life of the pavement.

So jointing is not a finishing detail. It is structural, and it is on the clock from the moment the concrete starts to set.

What are the joint types in concrete pavement?

Rigid pavement uses three working joint types, and naming them right is the first thing a concrete super checks on a new crew. Contraction joints, also called control joints, are the routine transverse and longitudinal joints sawed into the slab to control shrinkage cracking. They are the ones you place the most of. Construction joints form where placement stops and starts again, the planned cold joints at the end of a day's pour or a lane. Isolation joints separate the pavement from anything fixed it should not be tied to.

Isolation is where the old word expansion still confuses people. Full-width expansion joints with a compressible filler were standard decades ago, but on plain jointed pavement they are mostly gone, because the joint progressively closes, squeezes the filler, and lets the nearby contraction joints pull open instead. The modern term is isolation joint, and the ACPA and FHWA guidance treats it that way. You isolate the pavement at structures and fixed objects, not as a routine expansion device.

Use isolation joints where the slab meets something that moves differently or must not move it: bridge abutments, building foundations, drainage structures, light poles, hydrants, manholes, and at the boundary where new pavement meets old. The isolation joint runs full depth with a preformed compressible filler, no dowels or tie bars across it, so the pavement can move without prying on the structure. Confirm the joint detail against the project plans, because the layout and the filler material are spec items, not field calls.

How far apart should concrete pavement joints be?

A working rule of thumb sets the maximum contraction joint spacing at roughly 24 to 36 times the slab thickness, in consistent units, which is the same as 2 to 3 feet of spacing for each inch of thickness. A 6 in slab lands near 12 to 18 ft, an 8 in slab near 16 to 18 ft. ACI guidance for parking lots and the ACPA tools tend to the tighter end, on the order of 24 to 30 times thickness, often capped around 15 ft. The project and agency specification set the real numbers, so use the rule to sanity-check the plan, not to overrule it.

Keep the panels close to square. The aspect ratio, panel length divided by width, should stay at or under about 1.5 to 1. Long, skinny panels crack across the middle no matter how you space the joints, because a slab that is much longer than it is wide builds stress along its length faster than the joints can relieve it. If a layout forces a panel past 1.5 to 1, add an intermediate joint to break it up.

Two more things people miss. Joints should meet at right angles and line up across lanes, because an offset or skewed joint invites a crack to run from the joint end into the next panel. And small odd-shaped panels around manholes, inlets, and curb returns crack early, so isolate or block out those features and aim for regular panels around them. Lay the joint pattern out on paper before the pour, not with a saw after it.

When do you saw concrete pavement joints?

You saw the contraction joints as soon as the concrete is hard enough to cut without raveling the edge, and before random cracking starts. That window is the whole game. Open it too early and the saw tears and unravels the green concrete. Open it too late and the slab has already cracked where it wanted, and your sawed line is decoration. The window is short and it moves with the weather, the mix, and the slab thickness, which is why someone has to watch the slab, not the clock alone.

Two saws, two timetables. A conventional wet saw goes in once the concrete bears the weight without spalling, commonly in the range of 4 to 12 hours after placement. An early-entry, or green, saw rides on a skid plate and cuts much sooner, often in the range of 1 to 4 hours, which buys margin on a hot day when the slab is racing toward random cracking. On a fast-setting pour or a hot, dry, windy afternoon, that early window can slam shut in a couple of hours, so the early-entry saw earns its keep.

Cut depth is set by the slab. The conventional contraction joint goes to one quarter to one third of the slab depth, D/4 to D/3, deep enough to force the crack down to the notch. The early-entry saw cuts shallower by design, with a common minimum near 1 in for slabs up to about 9 in, because it relies on cutting so early that even a shallow notch controls the crack. Whichever saw, the crack forms below the cut within hours of sawing, often before you finish the next panel. If a panel cracks beside your joint instead of under it, the saw was late, full stop.

What is a dowel bar?

A dowel bar is a smooth, round steel bar set across a transverse joint to carry the wheel load from one slab to the next. As a tire crosses the joint, the loaded slab wants to deflect down and the next slab does not. The dowel ties their vertical movement together so the load transfers across the joint instead of slamming the leading edge of the next panel. That load transfer is what stops faulting, the little step that builds at a joint when one slab settles below its neighbor and beats the ride and the slab edge to death.

The dowel is smooth and round on purpose, and at least one half of it is debonded with grease, a plastic sleeve, or a bond breaker so it slides. It has to carry the vertical load while still letting the slabs open and close with temperature along the bar's axis. Bond a dowel solid on both ends and you have made a tie bar by accident, which locks the joint and cracks the slab when it tries to move. Common dowels run about 1.25 in diameter for slabs up to roughly 10 in, 1.5 in for thicker slabs, around 18 in long, on 12 in centers, set at mid-depth and parallel to traffic. The spec sets the exact size and spacing.

Two ways to set them. On fixed-form work, dowels ride in welded baskets staked to the subbase ahead of the pour, and the concrete places around them. On slipform paving, a dowel bar inserter pushes the bars into the fresh concrete behind the paver. Either way the bars must be parallel to each other, parallel to the surface, and parallel to the direction of travel. Hold the bars where they belong and the joint works for the life of the pavement.

Dowel bars vs tie bars: what is the difference?

Dowels and tie bars look similar and do opposite jobs, and mixing them up is one of the costly rookie errors in this trade. Dowels are smooth, sit across transverse joints, and transfer load while sliding. Tie bars are deformed, sit across longitudinal joints, and do not transfer load and do not slide. The deformations grip the concrete on both sides so the bar works in tension and holds the two lanes tight together. A tie bar's whole job is to keep adjacent lanes or panels from drifting apart and to keep the longitudinal joint from opening up and losing its own load transfer through aggregate interlock.

Run the two failures and the difference is obvious. Put smooth, greased dowels where tie bars belong and the lanes pull apart, the longitudinal joint opens, water gets in, and the joint stops carrying load across itself. Put deformed, bonded tie bars where dowels belong, across a transverse contraction joint, and you have locked a joint that needs to open and close with temperature, so the slab cracks somewhere to get the movement it was denied.

Tie bars are typically deformed bars on the order of #4 or #5, a couple of feet long, spaced a few feet apart, bonded full length. Dowels are smooth, larger, and debonded on one side. Same family, opposite intent: dowels carry load and let the slab move, tie bars hold the slab together and stop it from moving. The project plans call out which bar, where, and at what spacing, and that callout is not a place to improvise.

Placing the slab: fixed-form and slipform

Concrete pavement goes down one of two ways. Fixed-form paving sets steel or wood forms to grade, places concrete between them, and strikes it off, the method for lots, aprons, ramps, and anything irregular. Slipform paving runs a machine that carries its own moving forms, extrudes the slab to width and thickness in one pass, and is how mainline roads and large continuous areas get paved. The principles are the same. The slipform paver just does the consolidating, striking, and edging in a single continuous operation.

Consolidation makes or breaks the slab. Internal vibrators behind the paver, or a vibrating screed on fixed-form work, drive the air out and bring the concrete tight around the dowels and against the forms. Under-vibrate and you get honeycombing and voids. Over-vibrate and you drive the coarse aggregate down and bring a soupy, weak layer of paste and water to the top that will scale later. The fix is enough vibration, not maximum vibration, and a steady forward speed so every spot gets the same treatment.

Set the grade and the support before the truck shows up. Dowel baskets staked, tie bars placed, subbase trimmed to grade and moistened so it does not steal water from the bottom of the slab. A slab placed on a dry, dusty subbase loses water out the bottom and the bottom never cures right, the same lesson the cold-weather warning makes about a cold or frozen subgrade. The concrete is only as good as what it lands on and how tight you consolidate it.

Finishing and texture

Finishing concrete pavement is a light touch, and the discipline is knowing when to stop. After strike-off and consolidation, a bull float or a longitudinal float knocks down the ridges and closes the surface, and that is most of it. The cardinal rule is no finishing while bleed water is on the surface. Work bleed water back into the slab and you trap a weak, high-water layer right at the top, and that layer is exactly what dusts and scales under traffic and salt. Wait for the sheen to go, then finish. Overworking a pavement surface is the same mistake the broader concrete-finishing trade warns about, and on pavement it shows up as the part that wears.

Texture is the next move, and it is a safety item, not cosmetics. The finished surface needs friction so tires grip it wet, so you build in macrotexture before the concrete sets. A burlap or turf drag gives a fine texture for low-speed areas and lots. Brooming gives a coarser tooth. On higher-speed roads, tining drags a steel comb across or along the slab to cut grooves that channel water out from under the tire and hold skid resistance for years. Transverse or longitudinal tining, depth, and spacing are spec items, often tied to noise and friction requirements.

Timing ties it together. You texture once the surface has set enough to hold the pattern but is still workable, and then the cure goes on right behind it. On a paving train the float, the texture, and the curing spray follow the paver in close order, because every minute the textured surface sits open it loses the water the cure is there to keep. Texture, then cure, and keep them close to the paver.

How do you cure concrete pavement?

You cure concrete pavement by spraying a liquid membrane curing compound over the whole surface right after texturing, before the surface dries. Curing means keeping enough water in the concrete for the cement to keep hydrating and gaining strength. Pavement needs it more than almost any other concrete pour, because a slab is nearly all surface: thin, flat, and fully exposed to sun and wind. Lose that water and the top of the slab stops gaining strength, then dusts, scales, and crazes. The cure is not optional on pavement and it is not a step to short.

The standard is a liquid membrane-forming compound, white-pigmented, meeting ASTM C309, commonly the Type 2 white material. White earns its place twice over. It reflects sunlight and holds the slab temperature down, which fights early thermal cracking, and it shows you where you have and have not sprayed, so you can see a missed strip before it becomes a scaled strip. Common coverage runs about 1 gallon per 200 sq ft, near 1 gallon per 25 sq yd, and a tined or grooved surface usually gets two coats because the grooves drink more. The product datasheet and the spec set the rate.

Timing and uniformity are the field battle. Spray as soon as the free water is gone and the texture is set, while the surface is still damp, not after it has flashed off in the wind. Cover everything, including the edges and the faces of the slab on fixed-form work after you strip the forms. The worst pavement curing failures are not no-cure, they are late-cure and thin-cure: a crew that lets the textured surface sit ten minutes too long in the sun, or runs the spray rig too fast and lays a film you can see through. On a hot, dry, windy day, get the cure on fast, because that is the day the slab loses water fastest and the day the cure matters most.

Sealing the joints

Once the slab has cured and the joints are working, the contraction joints get widened at the top into a sealant reservoir and sealed, to keep water and incompressibles out. The narrow sawcut that controlled the crack is too tight to hold a flexible sealant, so a second pass widens the top of the joint into a reservoir sized to the sealant. A backer rod goes in below the sealant to set the depth, keep the sealant off the bottom of the joint, and control the shape, with the rod a touch larger than the reservoir so it stays put. The sealant fills above it and finishes recessed slightly below the surface so traffic does not pick it out.

Shape factor is the number that controls sealant life. It is the ratio of sealant depth to width, and a sealant stretched in the wrong proportion tears at the joint face when the slab moves. The backer rod is how you hit the right shape factor without overfilling. Too much sealant in a deep narrow slot is not better, it fails sooner.

Sealing keeps surface water from running down the joint into the subbase, where it feeds pumping and faulting, and it keeps sand and grit from packing the joint solid so the slab cannot close. Some agencies allow a no-seal approach on certain pavements, leaving narrow joints unsealed by design, and the maintenance plan and the spec decide which way a given job goes. Whatever the choice, it is a deliberate one, not a step that just got skipped.

When can you open concrete pavement to traffic?

You open concrete pavement to traffic when it has gained enough strength to take the load without damage, measured, not guessed. The slab does not care how many days have passed. It cares about strength, and strength depends on the mix and the temperature it cured at. A standard pour might reach opening strength in a week in good weather and longer in the cold, while a fast-track mix designed for early strength can open in a day or two when the schedule demands it.

Confirm it with a test, not the calendar. The common acceptance is a flexural strength, the modulus of rupture from a beam break, since the slab fails in bending, with opening targets often in the range of 350 to 450 psi flexural, or an equivalent compressive strength near 2500 to 3000 psi from cylinders. Many agencies now use the maturity method, where field temperature sensors track the time-and-temperature history of the slab and a calibrated curve estimates the in-place strength, so you open on the slab's actual strength instead of breaking extra beams. The target and the test are spec items.

Opening early is a real temptation and a real risk. Put trucks on a slab below its opening strength and you can crack panels, spall joint edges, and pull dowels loose from concrete that has not gripped them yet, and that damage is permanent. The number to hold is in the spec. Hold it.

Dowel misalignment and locked joints

A dowel only works if it is straight and aligned, and a misaligned dowel does the opposite of its job. The bar is supposed to slide along its axis so the joint can open and close. Tip it, skew it, or set it too high or low and the bar binds in the concrete when the slab tries to move. A bound dowel locks the joint, and a locked joint forces the shrinkage and thermal movement to come out somewhere else, usually as a crack near the joint or a spall right over the bar.

This is why dowel placement is inspected hard. The bars in a basket have to be parallel to each other, parallel to the slab surface, and parallel to the line of traffic, all at once. Baskets that shift during the pour, get run over by the placing equipment, or were never staked down right throw the whole row out of line. On slipform work a misadjusted dowel bar inserter can leave bars high, low, or skewed across a whole section before anyone catches it.

Catch it before the concrete sets, because after it sets the fix is to saw out and replace the joint. Some agencies run magnetic tomography over hardened slabs to map dowel position when a joint is misbehaving, which tells you whether a cracking problem is a dowel problem. The cheap insurance is staking the baskets solid, checking the inserter, and keeping the placing crew from dragging across the baskets.

Smoothness and profile

Pavement smoothness is a measured spec, and on bigger jobs it carries money. The classic field check is a straightedge, commonly 10 ft, laid on the fresh or hardened surface to find high and low spots against a tolerance like 1/8 in or 1/4 in under the straightedge. On highway and airfield work the acceptance moves to a profile measurement, an inertial profiler or a profilograph that scores the ride over the whole length, with incentive pay for a smooth slab and penalties or grinding for a rough one.

Most of the smoothness is built in before the concrete sets, at the paver and the screed, by holding consistent head of concrete, grade, and forward speed. You cannot finish your way out of a wavy strike-off. Where a hardened slab misses the spec or a joint faults, diamond grinding brings the profile back and restores texture at the same time, which is why grinding shows up both as a correction and as a planned smoothness treatment.

JPCP, JRCP, and CRCP

Concrete pavement comes in three families by how it handles reinforcement and cracking. Jointed plain concrete pavement, JPCP, has no structural steel in the slab, only dowels and tie bars at the joints, and it controls cracking entirely with closely spaced contraction joints. It is the most common type for streets, lots, and a lot of highway work, and it is what most of this guide describes.

Jointed reinforced concrete pavement, JRCP, spaces the joints farther apart and adds light steel mesh or bars in the slab to hold the intermediate cracks tight when they form between the wider joints. It was common in older highway construction and shows up less in new work. Continuously reinforced concrete pavement, CRCP, takes the idea to the end: a heavy continuous mat of longitudinal steel, no transverse contraction joints at all. CRCP is designed to crack, in fine, closely spaced transverse cracks that the steel holds tight enough to keep transferring load.

The choice is a structural design decision tied to traffic, life-cycle cost, and agency practice, not a field call. What changes in the field is the jointing and the steel: JPCP lives or dies on the contraction joints and the dowels, CRCP lives or dies on the steel placement and the laps. Build the type the plans call for, the way the plans detail it.

Hot and cold weather placement

Weather attacks the two jobs that define pavement: the cure and the jointing window. In hot, dry, windy conditions the slab loses water fast, the surface crusts while the inside is still soft, and the sawing window slams shut early because the slab races toward random cracking. The moves are practical: cool the mix and the subbase, place in the cooler part of the day, get the texture and the cure on fast, and have the early-entry saw ready because you may have only a couple of hours before the slab cracks on its own.

Cold is the opposite problem. Below about 40 degrees F the hydration reaction slows and strength gain stalls, and if the slab freezes before it reaches a set strength the paste is damaged for good. The number people miss is the subgrade. Place on frozen ground and the bottom of the slab never cures right no matter what you do on top. Keep the subbase from freezing, protect the fresh slab with blankets or heat, and plan the protection before the truck shows up, not after. The ACI cold-weather and hot-weather provisions give the framework, and the project spec sets the limits.

Cold also stretches the schedule. The sawing window opens later because the slab sets slower, and opening to traffic moves out because strength comes slower, which is exactly when the maturity method or extra cylinders pay off, so you open on real strength instead of a calendar that does not know it got cold.

Hardstands, generator pads, and heavy-load slabs

Concrete is the default for hardstands and equipment pads because the loads are heavy, slow, and concentrated, and often parked in one place for hours. A data center generator pad, a transformer pad, a crane hardstand, or a container stack sees point loads and sustained weight that would rut and shove asphalt, and it may also see fuel and oil that asphalt cannot live with. The rigid slab spreads that point load over a wide footprint, which is the property that makes it the right pavement here.

What changes on a heavy-load slab is the engineering, not the principles. The slab is thicker, the reinforcement and dowels are sized to the real load, and the subbase and drainage matter even more because a void under a heavily loaded slab edge fails fast. Isolation joints around the equipment, the bollards, the conduit stub-ups, and the foundation keep the pad from prying on what it serves. The jointing, the cure, and the support all still apply, just to a slab carrying a transformer or a genset instead of a delivery truck.

Treat these as designed structures and build to the structural drawings. The load is the reason the pavement is concrete in the first place, so the slab thickness, the steel, and the joint details are not the place to value-engineer on the fly.

Field checklist

What to document

The slab you cannot defend later is the one nobody wrote down. When a joint faults or a panel cracks a year out, the record is what tells you whether the joint was sawed in time, the dowels were aligned, the cure went on, and the slab was opened at strength. Capture it as you build, joint type by joint type.

For each pavement section, record the slab thickness and mix, the joint layout and spacing, the sawcut timing and depth and which saw, the dowel and tie bar size and spacing and placement method, the texture type, the curing compound and rate and timing, the joint sealing detail, and the strength and date the slab was opened to traffic. Note the weather on placement day, because the cure and the sawing window both hinge on it.

Common mistakes

• Sawing the joints too late, so the slab cracks at random and ignores the pattern you planned.
• Spacing the joints too far apart or letting panels go long and skinny past 1.5 to 1, which cracks the middle.
• Misaligning the dowels, tipped or skewed, so they bind and lock the joint and crack the slab.
• Confusing dowels and tie bars: smooth sliding dowels where lanes need to be tied, or bonded tie bars across a joint that must open.
• Skipping, delaying, or thinning the cure, so the surface dusts, scales, and crazes.
• Finishing while bleed water is still on the surface, sealing a weak high-water layer into the top.
• Placing on a dry, dusty, or frozen subbase so the bottom of the slab never cures right.
• Opening to traffic on the calendar instead of a measured strength, and cracking the panels you just built.

Standards and references

The framework for concrete pavement lives across a few bodies, and citing the right one is the credibility test. The American Concrete Pavement Association, the ACPA, publishes the working guidance on jointing, dowels, and tie bars that the trade leans on. ACI covers the concrete side, with ACI 330 for parking lots and ACI 325 documents for concrete pavement design and construction, and the FHWA technical advisories and DOT specs govern roadway and highway pavement. Confirm the current edition of each, because they revise on a cycle and the latest is what an owner or agency expects.

Materials and methods carry ASTM and AASHTO numbers. The curing compound is ASTM C309 for liquid membrane-forming compounds, Type 2 for the white-pigmented material used on pavement. Concrete strength testing runs through ASTM C39 for compressive cylinders, the flexural beam test for modulus of rupture used in pavement acceptance, and the maturity method under ASTM C1074 for estimating in-place strength. Dowel and tie bar steel, the curing, the texture, and the joint sealant all trace to ASTM or AASHTO material specs called out in the project documents.

Above all of it sits the project specification and the structural design from the engineer. The slab thickness, the joint layout, the dowel and tie bar schedule, the texture, the cure, the sealing, and the opening strength are spec items, and where a contract calls a number, that number controls over any rule of thumb in this guide. Do not invent a section number on a submittal. Name the requirement, cite the standard you have confirmed, and let the spec settle the value.

Units, terms, and conversions

Concrete pavement carries a vocabulary that shifts between the slab, the spec, and the lab sheet, so the same idea reads a few different ways across a job.

Rigid pavement and PCC (portland cement concrete) pavement mean the same thing. A contraction joint is also called a control joint. An isolation joint is the modern term for what older plans call an expansion joint. Slab thickness is in inches on US plans and millimeters on metric ones, and the joint-spacing rule of 24x to 36x thickness works in either as long as the units match. Curing compound coverage reads as square feet per gallon or square yards per gallon. Strength reads in psi or MPa, with a flexural modulus of rupture for pavement acceptance and a compressive strength from cylinders, and the maturity method reports an estimated in-place strength from temperature history.

Rigid / PCC pavement

A portland cement concrete slab that carries load by beam action, as opposed to flexible asphalt

Contraction (control) joint

A sawed plane of weakness that forces the shrinkage crack to a chosen line

Isolation joint

A full-depth joint separating the pavement from a fixed object; the modern term for an expansion joint

Dowel bar

Smooth round bar across a transverse joint that transfers load and slides on one debonded end

Tie bar

Deformed bar across a longitudinal joint that holds lanes together and does not transfer load

Shape factor

The depth-to-width ratio of a joint sealant, set by the reservoir cut and the backer rod

Maturity method

Estimating in-place strength from the slab's time-and-temperature history under ASTM C1074

Related tools

Calculators and readiness checks for this work

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