Codes & standards referenced
The Indian general workmanship code for concrete construction. The pour card's 14 checks are an operational reading of the workmanship clauses — formwork release and cleanliness, cover to reinforcement, placement rate, sampling frequency, vibration. The card is not a substitute for the code; it is the checklist the code expects the site team to operate against.
The Indian standard for the slump test — the apparatus (300 mm cone, 16 mm bullet-nosed rod), the procedure (3 layers, 25 rodding blows per layer, 3–7 s vertical lift), and the decision rule (true / shear / collapse; shear slump and collapse mean re-test, not record). Cluster B check 7 (sample drawn) and Cluster C check 8 (slump target re-confirmed) both run on this method. Mix the sample for at least 30 s after all ingredients are in the mixer or pan (per the project's mixing-time SOP) before drawing the slump specimen.
The US counterparts to the IS 1199 methods — useful when reading international specifications, plant operating procedures, or technical literature from US-based RMC networks. The geometry and intent match IS 1199 (Part 2), with minor procedural differences (e.g. ASTM C172 specifies the time-window for sampling after the final batch of concrete has been discharged into the mixer). Not a substitute for IS 1199 on Indian sites.
Why this matters
The difference between "a pour that went well" and "a pour that started well" is the checklist. A slab can be properly designed, properly mixed, properly transported, and still fail on the placement — because the formwork was inadequately released, the vibrator count was below safe ratio, the slump recheck after a 90-minute transit delay was skipped, or the pump operator couldn't see the placement crew through a pile of staged reinforcement. The cost of each of those failures surfaces two weeks later, on the cube report. By then, the slab, the truck, the decision and the contractor's schedule have all moved on. A pre-pour card doesn't catch every failure; it catches the failures you don't have time to remember when the pump is already on.
Failures on pour day cluster at predictable points. The formwork is checked by the contractor but the release-agent is missed in one bay. The slump is fine at the plant and 20 mm low at the pump because the transit took 35 minutes longer than planned. The pump arrives, the operator is shouting commands, the placement crew can't hear because of a diesel generator on the other side of the slab. Each of these failures has a check that catches it; none of the checks is exotic; the entire list fits on one side of an A4 sheet. The card is a forcing function for the predictable failures.
Formwork release and cover verification before the truck; sample, ticket and drum at the truck; slump, temperature, rate, line-of-sight at the pump; sample frequency, vibrator rotation, surface watch during placement. The same five points, the same five failure modes, on every pour.
A 28-day strength shortfall is the diagnostic that surfaces the failure — but the failure happened at the pump. The card is the only record that links the cube to the process that produced it. Without the card, the cube is a number without a story.
The card only works if one named person owns it for the duration of the pour. Without a card keeper, the checklist lives on a clipboard that gets put down when the first truck arrives. The card keeper is the one role the pour cannot do without.
The 4 clusters — 14 checks explained
The 14 checks are organised in 4 clusters by when they happen. Cluster A runs at -30 minutes, before the truck has left the plant. Cluster B runs as the truck pulls in. Cluster C runs at the pump, before and during the first concrete out. Cluster D runs continuously through placement. 4 + 3 + 4 + 3 = 14. The numbers are deliberate: the four clusters are the four predictable failure windows; the 14 checks are the minimum that closes each window.
Before the truck arrives · 4 checks
Run at -30 min. This is the cluster the verbal walkthrough usually misses — and the cluster the contractor is least likely to have a process for, because it happens before the pour is "live".
- Formwork released, clean, release-agent applied. Strip the previous pour's release-agent, sweep the soffit, re-apply. A missed bay reads as honeycomb at strike; the patch is the most expensive line on a slab BOQ.
- Reinforcement cover verified, spacers in place. Walk the slab with a cover meter or a 25/40/50 mm spacer gauge. Concrete doesn't read a drawing; it reads whatever the cover actually is on the day.
- Access for pump and transit mixers. Pump boom reach verified, transit mixer turning circle, chute reach. If the pump can't reach the far bay without re-positioning, the placement plan is wrong — not the access.
- Vibrator count, standby, needle sizes. Two vibrators per placement crew minimum, one on standby. Mix 40 mm and 25 mm needles for the column-to-slab transitions. A single vibrator on a 60 m³ pour is a recipe for honeycombing; the cube will pass, the slab will not.
As the truck arrives · 3 checks
Run as the truck pulls in. This is the cluster that catches the truck-side failures — wrong mix, wrong time, wrong truck. Every check here is a 30-second decision that prevents a 30-minute argument at the pump.
- Batch ticket reviewed (mix grade, time of batching, admixture). The ticket is the contract. Mix grade matches the pour card, batching time gives you the time-from-batch window, admixture row tells you whether retarder was dosed (it usually wasn't, in summer).
- Visual drum inspection (no segregation, no excess water). Look up the chute: aggregate pile-up at the back of the drum is segregation; free water pooling is over-batched. Both are reject-on-sight conditions.
- Sample drawn for slump and temperature before discharge. Per IS 1199 (Part 2):2018 — the 300 mm Abrams cone, 3 layers × 25 rodding blows, 3–7 s vertical lift, measure the subsidence. Record the number, the visual outcome (true / shear / collapse), the time, the temperature. Shear slump and collapse mean re-test, not record.
At the pump — first concrete out · 4 checks
Run at the pump, before and during the first concrete out. This is the cluster that catches the placement-side failures — wrong slump at the pump, hot concrete, pump rush, blocked line-of-sight. The "STOP if rushed" flag is on check 10 because the placement rate is the single most common cause of formwork failure on Indian sites.
- Slump target re-confirmed (e.g. 75 ± 15 mm for M30; spec-specific). Re-run the slump at the pump, not at the truck. The 35-minute transit ate 15–25 mm off the as-batched slump. The reading on the form's first row is the one that decides the pour; the second row is the one that decides the day.
- Concrete temperature within limits. Per IS 456 Cl 13.3, concrete temperature at placement should not exceed 40 °C as a maximum control limit; project specifications commonly set a lower limit, especially for mass concrete. IS 7861 (Part 1) — Hot Weather Concreting — frames the wider placement-temperature envelope and lists precautions for hot-weather work. Check and follow the project limit. If it is exceeded, reject or cool, not "place anyway". For cold-weather pours, IS 7861 (Part 2) sets the minimum concrete temperature at placement at 5 °C.
- Placement rate matches pump capacity (STOP if rushed). The formwork has a rate limit. The pump has a capacity. If the pump can out-pour the formwork, the contractor will let it, and the formwork will move. The card keeper's job is to say STOP, drop the pump output, and place at the rate the formwork can take.
- Line-of-sight between pump operator and placement crew. The pump operator and the placement crew communicate by hand signal and shout. If the line-of-sight is blocked by a pile of staged reinforcement, a generator, or a stack of plywood, the communication breaks and the pour becomes a guess. Move the obstruction first.
During placement · 3 checks
Run continuously through placement. This is the cluster that catches the in-pour failures — sampling gaps, vibrator crew fatigue, surface defects that show up only while the concrete is still wet.
- Sample frequency (per IS 456 sampling frequency). The IS 456 sampling frequency gives a cube sample for every defined quantity of concrete — one of the levers in the characteristic-strength calculation that the card is feeding into. Skip a sample, lose a data point, weaken the statistical case the cube register is trying to make.
- Vibrator rotation. Two operators on a slab, one on a column, switching every 30 minutes. Vibrator fatigue produces under-vibrated zones that read as honeycomb at strike. The rotation is the cheapest productivity gain on the pour.
- Bleeding and honeycombing watch. While the concrete is still plastic, the surface is the diagnostic. Bleed water pooling means the mix is over-wetted or the air is trapped. Honeycombing at the formwork face means under-vibration, too-stiff a mix, or a release-agent miss. Both are visible only in the placement window.
How to apply — the printable one-pager
A single A4 sheet, printed, carried on site for the duration of the pour. The card is intentionally low-fi: real <input type="checkbox"> elements (not visual marks), plain text labels, signature lines for the pour date, mix grade, and the card keeper. Print at 100 % on A4; the card is a forcing function, not a poster.
5-step usage on site
- Print the card. One A4 sheet per pour. Fold once, carry in a clear plastic sleeve to keep the formwork cement off the checkboxes.
- Assign a card keeper. One named person — typically the QC technician or the site engineer's representative — owns the card for the duration of the pour. The card keeper is the one role the pour cannot do without.
- Run Cluster A at -30 min. Before the truck has left the plant. Catch the formwork, cover, access and vibrator failures in the window where they are still fixable.
- Run Cluster B as the truck arrives. Batch ticket, drum visual, sample drawn. Reject at this stage is a 30-second decision; reject at the pump is a 30-minute argument.
- Run Cluster C at the pump, Cluster D during placement. Slump recheck, temperature, placement rate, line-of-sight, sample frequency, vibrator rotation, surface watch. File the card with the cube register when the pour is complete.
Concrete Pour Card
ConcreteInfo · 14 checks · 4 clusters
IS 456 · IS 1199 (Pt 2)
Cluster A · Before the truck arrives
4 checksCluster B · As the truck arrives
3 checksCluster C · At the pump — first concrete out
4 checksCluster D · During placement
3 checksFile this card with the cube register. 4 + 3 + 4 + 3 = 14.
What goes wrong — top 5 failures the card prevents
Five failures show up on every site's "pour that went wrong" list. Each is caught by a specific check on the card; none is exotic. The 14-check format exists because the failures are 14-check-format too.
The contractor has checked the formwork; the soffit has been swept; the release-agent has been applied to three of four bays. The fourth bay was missed. The pour starts; 6 m² of honeycomb at strike; patch repair; the patch is the most expensive line on the slab BOQ. Caught by: Cluster A check 1.
The truck arrives, the slump looks right by eye, the pump is on, the placement crew is waiting. No sample, no number, no record. The cube cast from the truck is the only data point. The cube fails at 28 days; the conversation is "but it looked right". Caught by: Cluster B check 7.
One vibrator on a 60 m³ pour. The vibrator operator is working flat-out, the column-to-slab transitions are under-vibrated, the cube will pass, the slab will not. Honeycomb at strike, patch repair, programme loss. Caught by: Cluster A check 4 + Cluster D check 13.
The pump is at full output. The formwork is not designed for the rate. The formwork moves. The slab is rejected. The contractor's response is "the formwork is rated for more" — the photo says otherwise. Caught by: Cluster C check 10 (the "STOP if rushed" flag).
The truck took 95 minutes from batching. The as-batched slump was 110 mm; at the pump it is 75 mm. The 75 mm is in the spec band — but the margin is gone, and the cube is going to be tight at 28 days. The pour is placed anyway because the number "looks fine". The cube fails. The conversation is "but the slump was 75 mm". Caught by: Cluster C check 8, in combination with the time-from-batch column on the fresh-concrete log (see also Q3).
Field-checklist blocks
A short questionnaire, an inspector's checklist, and three worked examples that show how the 14-check card resolves into a decision on site.
Questionnaire — ask before the pump starts
- Has Cluster A been run at -30 min — formwork released and clean, release agent applied, cover verified, pump and transit access clear, vibrator count and standby confirmed?
- Has the truck-side verification (Cluster B) been completed — batch ticket reviewed, drum visual clear, sample drawn for slump and temperature per IS 1199 (Part 2):2018?
- Has the slump been re-confirmed at the pump (Cluster C check 8) after accounting for time from batching, with a margin against the project specification band?
- Is the concrete temperature within the IS 456 Cl 13.3 limit (≤ 40 °C unless the project specification sets a lower value), and within the IS 7861 hot-weather envelope for the day's conditions?
- Is the placement rate matched to the formwork's design pressure rating and rate-of-rise limit, with the pump operator and placement crew in line-of-sight?
- Who is the card keeper — one named person who owns the card for the duration of the pour and signs it before it goes to the cube register?
- Has the lab schedule for the day been confirmed — cube curing tank temperature within the IS 516 envelope (27 ± 2 °C), machine calibration current, sample retention policy understood?
Inspector's checklist — what to verify on site
- Formwork release & cover: walk the entire formwork bay-by-bay; mark every missed release-agent strip; gauge every cover spacer against the design value.
- Vibrator count and standby: two vibrators in use, one on standby, with 40 mm and 25 mm needles for the column-to-slab transitions; operator rotation every 30 minutes.
- Slump at the pump: 300 mm Abrams cone, 3 layers × 25 rodding blows, 3–7 s vertical lift; record subsidence, type (true / shear / collapse), concrete temperature, time-from-batch; mix the sample for at least 30 s after all ingredients are in the mixer or pan.
- Sample frequency: cast one cube per the IS 456 Cl 15.2.2 frequency for the member and quantity; record on the cube register with the batch ticket number.
- Curing tank temperature: confirm the lab tank reads 27 ± 2 °C before the day's first cube goes in; record on the cube register.
- Sign-off: card keeper, site engineer and client / PMC witness sign the printed card; file with the cube register the same day.
What happens if… three worked examples
What happens. Truck #2 slump at the pump is 78 mm — inside the spec band but with little margin left after the 65-minute transit delay; the card keeper records the result and time, asks the site engineer to confirm placement, casts the cube and files the card with the cube register; 28 days later the cube returns ~26.8 MPa against the M30 target.
Likely outcome. Cube below characteristic strength; the pour card supplies the missing process record (transit delay, pump slump, decision to continue); the discussion moves from "the mix was wrong" to a documented margin analysis against IS 456 Table 11 group-of-4 and individual-result rules.
Preventive correction next pour. Tighten the transit-time ceiling in the pour card; reject a late truck with slump at the lower edge of the spec band; or specify a richer mix at the pump with a retarder in summer.
What happens. Strip-out the next day shows a 6 m² area of honeycombing on the missed bay; patch repair is the most expensive line on the slab BOQ.
Likely outcome. Patch-repair line item, lost programme, and an audit finding against Cluster A check 1; the consultant's report references the missing card and the absent pre-pour walk.
Preventive correction next pour. Run Cluster A at -30 min every time, including a felt-tip mark on every missed strip; do not start the pump with any checkbox still open.
What happens. The formwork moves; the slab is rejected on cover and geometry grounds; the contractor's "the formwork is rated for more" claim is contradicted by the photographs taken at the time.
Likely outcome. Demolition and re-pour of the affected bay; programme loss; an audit finding against IS 456 workmanship clauses and the project quality plan; the card-keeper role is reviewed for delegation.
Preventive correction next pour. Insist on the card keeper saying STOP when the pump outpaces the formwork; drop the pump output, place at the rate the formwork can take; do not allow the placement rate to be set by truck queue pressure.
References & further reading
- IS 456:2000 (Amend. 6:2024) — Plain and Reinforced Concrete — Code of Practice (Fourth Revision). Bureau of Indian Standards. The general workmanship code for concrete construction. The pour card's 14 checks are an operational reading of the workmanship clauses; the card is not a substitute for the code, it is the checklist the code expects the site team to operate against.
- IS 1199 (Part 2):2018 — Fresh Concrete — Methods of Sampling, Testing and Analysis — Part 2. Bureau of Indian Standards. The slump test method (300 mm cone, 16 mm bullet-nosed rod, 3 layers × 25 rodding blows, 3–7 s vertical lift) and the decision rule that shear slump and collapse mean re-test rather than record. Cluster B check 7 and Cluster C check 8 both run on this method.
- IS 7861 (Part 1) — Code of Practice for Extreme Weather Concreting — Part 1 Hot Weather. Bureau of Indian Standards. Placement-temperature envelopes, hot-weather site practices, and the wider reading around Cluster C check 9. Verify the current edition against the BIS catalogue.
- IS 7861 (Part 2) — Code of Practice for Extreme Weather Concreting — Part 2 Cold Weather. Bureau of Indian Standards. Minimum concrete temperature at placement (5 °C), cold-weather precautions, and the cold-weather complement to the hot-weather Part 1.
- IS 516:2021 — Hardened Concrete — Methods of Test. Bureau of Indian Standards. The compression-test method referenced from IS 456 Cl 16. The cube result that the pour card feeds into 28 days later.
- ASTM C143 / C143M — Standard Test Method for Slump of Hydraulic-Cement Concrete. ASTM International. The US counterpart to the IS 1199 slump test method; useful when reading international specifications and plant operating procedures.
- ASTM C172 / C172M — Standard Practice for Sampling Freshly Mixed Concrete. ASTM International. The US counterpart for sampling practice; specifies the time-window for sampling after the final batch of concrete has been discharged into the mixer. Useful when reading US-based RMC plant procedures.
Year notes: IS 456 was first published in 1953 and is now in its Fourth Revision (2000) with multiple amendments; the current amendment status should be verified against the BIS catalogue before tendering. IS 1199 (Part 2):2018 is the most recent revision at the time of writing. IS 7861 (Part 1) on hot-weather concreting and IS 7861 (Part 2) on cold-weather concreting frame the wider temperature envelope; verify current edition and confirmation year against the BIS catalogue. IS 516:2021 is the compression-test method; the cube curing envelope is 27 ± 2 °C and the compression machine requires periodic calibration (commonly annual). ASTM editions should be checked against the current ASTM volume before use.
Frequently Asked Questions
Related articles
Slump Test vs Slump Flow — When Each Is Right
The fresh-concrete tests that close Cluster B and re-open it on every late truck. IS 1199 for vibrated concrete, EFNARC for SCC, and the 25-blow rodding mistake.
Acceptance Criteria — IS 456 Table 11
The fck + 0.825σ / fck + 3 MPa rules, the 4-sample and 1-sample exceptions, and what to do when a single cube fails. The downstream link from the pour card.
Honeycombing in Concrete — Causes, Prevention, Repair
The honeycomb at strike that the card's Cluster A check 1 (formwork release-agent) is designed to prevent. IS 456 Cl 7.4, the failure mode, and the patch.
Amit Haridas
Founder & Proprietor, ConcreteInfo. 25+ years of experience in concrete technology, RMC plant operations, construction quality, consulting and technical training across India.