Workability Calculator | Slump Adjustment Tool 2026 — MixDesignCalc

📅 IS 10262:2019 · IS 1199 · 2026

Workability Calculator

Slump selection by application, water adjustment for slump change, SP dosage for target slump, pumpability assessment, slump loss prediction and complete IS 10262 Table 2 water content reference

💧 Slump Selection by Application 📈 Water vs Slump Adjustment ⚙️ SP Dose for Target Slump ⏳ Slump Loss Predictor 🚯 Pumpability Assessment

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Slump Selection by Application

IS 10262:2019 Cl. 5.4 — Recommended slump ranges for common concrete placement conditions

10–25 mm

Very Low / S1

Mass concrete · Roads & pavements (VeBe preferred) · Precast with strong vibration · Plain footings

25–75 mm

Low–Medium / S2

General RCC (columns, beams, walls) · Footings with light rebar · Slabs placed by crane · Normal-pour structural concrete

75–100 mm

Medium / S3

IS 10262 standard design slump · RMC general delivery · Bridge decks · Pumped concrete (min recommended) · Heavily reinforced sections

100–150 mm

High / S4

Pumped concrete (preferred) · Congested reinforcement · Tremie pours · Difficult placements · In-situ piles

150–200 mm

Very High / S5

Self-compacting approach (use with VMA) · Drilled shafts · Very congested sections · Pre-qualify with SCC testing if >175 mm

Select Application to Find Recommended Slump

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IS 10262 Table 2 — Water Content Reference

IS 10262:2019 Table 2 — Design water content (L/m³) for crushed aggregate by MSA and slump. Rounded aggregate: deduct 10 L/m³. M-Sand: add 5–12 L/m³.

Aggregate Type

Highlight MSA

Highlight Slump

MSA \ Slump →	25 mm	50 mm	75 mm	100 mm	125 mm	150 mm

IS 10262 Table 2 Adjustment Notes: Values above are for crushed granite/basalt aggregate. Rounded aggregate (river gravel): deduct 10 L/m³. M-Sand: add 5–12 L/m³ depending on stone dust content (higher stone dust → higher adjustment). Fly ash PPC: spherical FA particles may reduce water 5–8 L/m³ vs OPC with same aggregate. All values assume Zone II sand; Zone III/IV sand adds 6–18 L/m³ to required water.

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Water Content Adjustment for Slump Change

Calculate how much water to add or remove to shift from a known slump to a target slump — with cement content recalculation to maintain w/c

Current Slump (mm)

Target Slump (mm)

Current Water Content (L/m³)

Current Cement Content (kg/m³)

Adjustment Method

Aggregate Type

✅ Water Adjustment Results

Slump Change

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Water Adjustment

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L/m³

New Water Content

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L/m³

New Cement Content

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kg/m³

w/c Ratio

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maintained

Strength Impact

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vs original

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IS 10262 Cl. 5.4 — Water-Slump Relationship: For crushed aggregate concrete, each 25 mm increase in slump requires approximately +6 to +9 L/m³ additional water. To maintain the design w/c ratio, cement must also increase proportionally. The preferred approach for raising workability without extra water (and cement) is to increase superplasticiser dosage — this is the IS 10262 recommended method for achieving higher slump at M30+.

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Superplasticiser Dose for Target Slump

Calculate the SP dosage required to achieve a target slump from a base slump without changing water content — maintaining design w/c ratio

Base Slump (no SP) (mm)

Mix workability without any SP at design water content

Target Slump (mm)

Cement Content (kg/m³)

SP Type

Ambient Temperature (°C)

Cement Grade

✅ SP Dosage Results

Slump Increase Needed

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SP Dose (% cement)

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% by mass

SP Volume per m³

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L/m³

SP Volume per m³ (NSF)

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L/m³ (if NSF)

Saturation Check

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Slump Retention

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at 30°C

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⚠️ Important: SP dosage for target slump must always be verified by a trial mix on your production cement. The saturation dosage — beyond which additional SP entrains air without further slump gain — varies by cement chemistry (C3A content, alkali level) and must be determined by the Marsh cone test or mini-slump test on paste. Never add more SP beyond saturation dosage in the field.

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Slump Loss Predictor

Estimate slump at delivery / placement based on mix design, SP type, temperature, and transit time

Initial Slump at Batching (mm)

SP Type Used

Ambient Temperature (°C)

Cement Grade

Cement Content (kg/m³)

w/c Ratio

Fly Ash / SCM Addition? (%)

SCM slows hydration → better retention

Required Slump at Placement (mm)

Minimum slump needed at point of pour

⏳ Predicted Slump Profile Over Time

Usable Window

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above required slump

Slump at 30 min

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Slump at 60 min

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Slump at 90 min

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Max Transit Time

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minutes

SP Type Verdict

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Slump Loss Rule of Thumb (IS 4926 Guidance): At 30°C, expect 25–35 mm/30 min slump loss with NSF SP; 10–20 mm/30 min with PCE Type F; 5–12 mm/30 min with PCE Type G. Above 35°C, these rates approximately double. IS 4926 specifies that RMC concrete shall be discharged within 2 hours of water contact or 300 drum revolutions, whichever is first — and slump shall be within specification at the point of delivery.

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Pumpability Assessment

Check whether your concrete mix is suitable for pump delivery — IS 4926, ACI 304.2R and pump manufacturer guidelines

Slump at Point of Pumping (mm)

Maximum Aggregate Size (mm)

Pump Line Diameter (mm)

Vertical Pumping Height (m)

Horizontal Run (m)

Cement Content (kg/m³)

% Passing 300 µm (Fine Agg)

From sieve analysis; governs pump lubrication

Fine Aggregate Content (kg/m³)

🚯 Pumpability Assessment Results

MSA / Pipe Check

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max 1/3 pipe dia

Slump Suitability

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for pumping

Fines Content Check

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lubrication adequacy

Equivalent Line Length

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m (1m vert = 8m horiz)

Overall Verdict

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Recommended Slump

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mm at pump

        📌 Pumpability Key Rules (ACI 304.2R / IS 4926)
        MSA limit: Maximum aggregate size ≤ 1/3 of pump pipe internal diameter (20mm MSA → minimum 75mm pipe; 40mm MSA → minimum 125mm pipe)
Slump at pump: Minimum 75 mm; optimal 100–150 mm. Below 75 mm → high pipe pressure → blockage risk
Fines content: % passing 300 µm sieve × FA content should provide adequate paste for pipe lubrication. Cement + fines > 400 kg/m³ recommended for reliable pumping
Equivalent line length: 1 m vertical rise = 8 m horizontal equivalent. Total equivalent length determines pump pressure requirement
Slump tolerance: ±25 mm at delivery; if outside range, investigate moisture correction, do not add site water

    

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Workability Test Methods — IS 1199 Reference

Conversion between workability measurement methods — Slump, VeBe, Compaction Factor, and Flow Table (IS 1199:2018)

Measured Value

Measured By

📊 Workability Equivalents

Slump (mm)

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IS 1199 Part 2

VeBe Time (sec)

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IS 1199 Part 3

Compaction Factor

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IS 1199 Part 4

Flow Table (%)

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IS 1199 Part 5

Workability Class

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Recommended Use

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Workability	Slump (mm)	VeBe (sec)	Compaction Factor	Flow Table (%)	IS Classification	Typical Use
Very Low	0–25	>12	0.75–0.80	<340	S1	Mass concrete; roads; precast (ext. vibration)
Low	25–75	6–12	0.80–0.85	340–380	S2	Lightly reinforced sections; footings; plain concrete
Medium	75–100	3–6	0.85–0.92	380–410	S3	Normal reinforced concrete; IS 10262 design slump
High	100–150	1–3	0.92–0.95	410–450	S4	Heavily reinforced; pumped concrete
Very High	>150	<1	>0.95	>450	S5	Tremie; drilled shafts; SCC approach

Workability Calculator

💧Slump Selection by Application

📋IS 10262 Table 2 — Water Content Reference

📈Water Content Adjustment for Slump Change

✅ Water Adjustment Results

⚙️Superplasticiser Dose for Target Slump

✅ SP Dosage Results

⏳Slump Loss Predictor

⏳ Predicted Slump Profile Over Time

🚯Pumpability Assessment

🚯 Pumpability Assessment Results

📌 Pumpability Key Rules (ACI 304.2R / IS 4926)

📊Workability Test Methods — IS 1199 Reference

📊 Workability Equivalents

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Slump Selection by Application

📋
IS 10262 Table 2 — Water Content Reference

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Water Content Adjustment for Slump Change

⚙️
Superplasticiser Dose for Target Slump

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Slump Loss Predictor

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Pumpability Assessment

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Workability Test Methods — IS 1199 Reference