Silo Slipform Systems

Silo Slipform
Systems

WORK PROCESS

The silo slipform construction process

01

Needs Analysis

Silo diameter, height, concrete regime and the 24-hour slipform programme are confirmed during the site survey.

02

Quotation & Preliminary Plan

The slipform method, hydraulic climbing and site resources are planned together with the quotation.

03

Calculations

Loads, form cross-section, pour rate and setting time are calculated specifically for the slipform operation.

04

Detailed Engineering

Reinforcement, hydraulics and verticality control are combined in a single set of slipform drawings.

05

Preparation & Safety

Platforms, guardrails and access are built into the OHS plan together with the slipform installation.

06

Slipform Execution

The form climbs hydraulically; continuous pouring means no cold joints.

07

Handover & Review

Level, verticality and pour records are handed over to the operator, and the slipform site is closed out.

EXECUTION

Our engineering approach
to slipform construction

01Slipform Systems
Silo Slipform Systems — Analysis

Analysis

Cross-section, concrete grade and the 24-hour slipform pace are set to suit the site. Wind, setting and hydraulics are assessed within the same plan.

02Slipform Systems
Silo Slipform Systems — Engineering

Engineering

Formwork, reinforcement and climbing increments are resolved in a single slipform design. Verticality tolerances are set out before work begins.

03Slipform Systems
Silo Slipform Systems — Slipform execution

Slipform execution

As the slipform rises on site, pouring, OHS and survey work run within the same shift. A report on the monolithic shell is provided at handover.

ABOUT THE SERVICE

Continuous, rigid shells
with silo slipforming

Silo slipforming is a specialised construction method for building tall reinforced-concrete structures that store cement, clinker, raw meal, grain, lime, minerals and other bulk materials quickly, under full control and as a single integrated structure. For silos that are tall, keep a largely constant cross-section and depend on the continuity of their reinforced-concrete walls, a slipform system offers a fundamentally different way of working from conventional formwork. It is far more than formwork equipment: it is a continuous construction process in which concrete production, reinforcement fixing, embedded items, working platforms, the hydraulic lifting system and site organisation are all managed together.

Rayf Teknik draws up the execution plan for each silo project around the structure's diameter, height and wall thickness, the material to be stored, the design geometry and site conditions. Once the formwork has been assembled at the starting level, concreting proceeds in a controlled sequence and hydraulic lifting units raise the form step by step. While the placed concrete gains sufficient strength, fresh concrete, reinforcement and any required embedded items are installed at the upper working level. This allows tall silo shells to rise steadily and without interruption.

Continuity of operations is one of the most critical factors in silo construction. Concrete setting time, ambient temperature, wind, concrete supply capacity and crew productivity must all be in step. For this reason, the entire process, from concrete supply to the shift pattern, is planned before slipforming begins. Ensuring that reinforcement fixing never falls behind the pour rate, continuously checking the form level and measuring the structure's verticality are fundamental parts of the operation.

Slipform systems serve a wide range of sectors, from cement, raw meal and clinker silos at cement plants to grain storage facilities. Because every silo serves a different purpose, applying the same formwork configuration directly to every project would be a mistake. Any hoppers, openings, doors, gallery connections, equipment anchorages or process penetrations within the silo must be incorporated into the design before climbing begins.

Rayf Teknik's approach goes beyond raising the reinforced-concrete shell: the structure must also be made compatible with the processes that follow. The silo superstructure, structural steel connections, equipment openings and required anchorage points are all assessed alongside the construction programme.

A well-planned silo slipform operation delivers a steady production flow on tall reinforced-concrete storage structures. The key advantage of slipform technology is that it minimises interruptions along the reinforced-concrete shell and largely eliminates the repeated erection and stripping of conventional formwork. The result is a controlled construction process in which the site, concrete, reinforcement and formwork crews advance in coordination within a single production programme.

TECHNICAL SPECIFICATIONS

Slipform technical specifications

The slipform climbing rate is adjusted to concrete setting, cross-section and weather conditions. The values below are typical site ranges; the exact programme is confirmed during the site survey.

Specification Value
01 System Slipform
02 Climbing rate 150–300 mm, governed by setting time
03 Geometry Square, rectangular, cylindrical, hyperbolic
04 Operation 24-hour site programme
05 Cold joints None
06 Assembly Single installation, hydraulic climbing
Silo Slipform Systems

TECHNICAL ADVANTAGES

Why slipform?

Slipforming eliminates cold joints in silos and chimneys. The advantages are set out point by point.

RAYF

01

Continuous Pouring

The slipform climbs hydraulically and concreting never stops. No cold joints form, so the shell remains monolithic.

Large-scale industrial facility working at night

SLIPFORM SUPPORT

Get expert support
from Rayf Teknik
for your slipform projects.

Our technical team will contact you to arrange a site survey and quotation for your silo slipform, chimney and tall-structure projects.

Information & FAQ

Frequently asked questions about slipforming

How slipforming works, how it differs from climbing formwork, where it is used and its key advantages.

What is a slipform system and how does it work?

Slipforming is a formwork method developed to raise tall reinforced-concrete structures continuously. The system is assembled at the starting level and, as the concrete sets, hydraulic equipment lifts the form in a controlled manner. Reinforcement fixing, concrete pouring and form movement all progress within the same work cycle. Continuous pouring reduces the risk of cold joints along the wall, and the shell behaves as a more integral reinforced-concrete structure. The climbing rate is adjusted to concrete setting, weather conditions and cross-section geometry. The method can be applied to cylindrical, square, rectangular and bespoke shapes.

The climbing increment is never taken from a catalogue; it is determined by reading that day's concrete consistency, weather and reinforcement progress together. If the hydraulic balance is disturbed, work is stopped, measurements are taken and only then does climbing resume. A summary of these daily adjustments can also be included in the handover file.

What is the difference between slipform and climbing formwork?

The fundamental difference lies in how the formwork advances. With slipforming, the equipment is assembled once and climbs continuously as the concrete gains strength; it is not dismantled and re-erected at each level. With climbing formwork, concrete is poured in defined lifts and, once the required strength is reached, the form is moved up to the next level. For continuous wall geometries such as circular silos and chimneys, slipforming can be the better choice in terms of both programme and joint continuity. For straight, lower walls, climbing formwork may also be preferred. The decision is based on height, cross-section, concrete programme and site access.

With climbing formwork, crane swing and anchor removal introduce their own risks, whereas slipforming relies on a continuous platform arrangement. Mixing the two in the same quotation distorts both the programme and the safety calculations. The chosen method is locked in with a written site survey note.

What types of structures is slipforming used for?

The method is used for cement, clinker, raw meal and grain silos, industrial chimneys, bridge and viaduct piers, water tanks, digesters and tall reinforced-concrete towers. What they have in common is the need for reinforced-concrete walls that continue vertically. The form is not limited to circular sections: square, rectangular, polygonal and hyperbolic shapes can also be engineered. Embedded plates, openings and process connections are incorporated into the drawings before climbing begins, so that the site, concrete and reinforcement crews advance on the same programme.

If openings, doors and process penetrations are added after climbing has started, the integrity of the wall is compromised. These elements are therefore included in the initial installation drawings, and the site crew fixes the reinforcement without missing any of the listed levels.

What are the main advantages of a slipform system?

The most obvious gain is that a tall shell can be raised under control without repeated stripping and re-erection of formwork. Silo construction that takes a long time with conventional methods can be shortened considerably with a properly planned slipform programme. Continuous pouring reduces cold joints, and loads can be expected to be distributed more evenly along the wall. Because the form is assembled only once, frequent crane-handled dismantling is reduced and platform-based working comes to the fore. Existing equipment can be adapted for subsequent projects through modification, and site supervision can also be provided to companies that purchase the system.

Speed alone is not a measure of success. If there is any verticality deviation, surface voids or irregular setting, the programme is slowed down. The goal is not a weak shell built quickly, but a rigid wall that holds its dimensions. This is where site supervision becomes essential.