slump.IO

Design professional concrete mixes in seconds. ACI, IS & BS standards built in. Export PDF reports. Works fully offline — no account needed.

slump.IO is a concrete mix proportioning tool for field engineers, lab technicians, and researchers who need fast, standards-based guidance in the field or lab.

All results are calculation aids only. Always validate proportions before field or structural use. slump.IO is not affiliated with or endorsed by ACI, BIS, BSI, or any standards body.

DESIGN PROCEDURES

• ACI 211.1 — Absolute volume method with water content tables, air content, W/C ratio, and coarse aggregate fractions
• IS 10262:2019 — Direct Table 2 water content lookup for 10, 20, and 40mm aggregate sizes
• BS 8500 — DoE proportioning method for UK and international practice
• Custom Mix Mode — Specify binder content and W/B ratio directly; ideal for UHPC, HPC, and research trial mixes

ADVANCED MATERIALS

• Dual SCM support — combine two supplementary cementitious materials in one design
• Fly Ash, GGBS, Silica Fume — with ACI efficiency k-values applied automatically
• W/CM ratio calculated from total cementitious content
• Volume balance check for custom mix designs

FIELD-READY FEATURES

• Aggregate moisture and absorption corrections
• Hot and cold weather guidance per ACI 305R and ACI 306R
• Metric and Imperial units for ACI designs
• Validation messages in the correct unit system

REPORTS AND ARCHIVE

• PDF mix design reports with your name, company, and project details
• Save unlimited mix designs locally
• Search by name or notes
• Edit and recalculate any saved design

FIELD TEST GUIDES

• Slump Test — ASTM C143
• Air Content — ASTM C231
• Fresh Density — ASTM C138
• Concrete Temperature — ASTM C1064

PRIVACY AND OFFLINE

• 100% offline — all calculations run on-device
• No account, no login, no subscription
• No data ever leaves your device

slump.IO is built by a concrete researcher. Download free and use as a guide — always verify before field use.