MANUFACTURING


Manufacturing Diagram

Siporex is produced by a highly complex and advanced manufacturing process in our factory under the careful control of chemists and engineers. Siporex is made either as steel reinforced panels using moulds 6 meters long, 1.5 meters wide and 600 mm deep or as non-reinforced blocks using moulds 6 meters long, 1.5 (or 1.2) meters wide and 600 mm deep.

A schematic diagram of manufacturing process is shown below:

 

Manufacturing Process


The basic raw materials are sand, water, aluminum powder and cement. The sand is ground to required fineness in a ball mill before mixing with other raw materials with water to form slurry to which a trace of aluminum powder is added as expanding agent.

All Siporex panels are reinforced with steel. Steel coils are straightened, cut and spot-welded into mats, where crossbars provide anchorage to the longitudinal reinforcements. Siporex blocks are not reinforced.


After dipping the welded mats in a homogenized anti-corrosion mix for rust protection, they are dried and assembled into cages and set accurately in the moulds before the slurry is poured in.

Regulated amount of aluminum powder gives accurate control of density of the final product.

Moulds are only partly filled with slurry which then expands in a controlled reaction to fill the moulds.


When the mass is sufficiently hard, the moulds are stripped and the cake is wire-cut to close tolerances into panels and blocks using high-precision cutting technology. These are then steam cured under high pressure in autoclaves for up to 15 hours. This completes the chemical process, resulting in a unique crystal structure of calcium silicate hydrate and ensuring a stable and inert product giving AAC outstanding qualities not found in other products.

 


After cooling to ambient temperature, the panels are demoulded and milled to required profile as necessary. All Siporex panels are singled out for proper marking, and if required, dry cut and stacked for further handling and storage.

The blocks are demoulded, strapped, marked and stored on wooden pallets. The finished goods inspection programme ensures the products quality. The material is now ready for loading and delivery.

 

 

 

 

 

 

 


Quality Control


The manufacturing of Aerated Lightweight Concrete as blocks and reinforced panels (Roof slabs, Wall panels & Lintels) by LCC Siporex implements and maintains a Quality Management System which fulfills the requirements of ISO 9001:2015.

It is the policy of LCC Siporex to provide quality products or services that always meet or exceed the expectation of the customer from inquiry to final delivery of the products / services.

Quality Control and Quality Assurance at LCC Siporex encompass both raw materials and finished products. Raw materials certificates are obtained from suppliers of cement, aluminum powder and reinforcement steel. In-house quality assurance is made for silica sand, cement, gypsum, Magnesite, lime, steel protection coating, aluminum powder and process water.

For final products, compressive test, shrinkage and dry densities are carried out on a daily basis. A load test for crack and rupture is performed on a load testing machine for slabs to ensure product quality of reinforced panels.

 

 

 

 


Material Identification & Markings


Siporex Blocks:
After autoclaving, Siporex blocks are ready for packing and distribution. Blocks are strapped in bundles and marked with a stamp denoting block dimension, density type and batch number. Bundles of blocks are arrange in stacks laid on wooden pallets and sent to storage or distribution.

 

 

 

 

 

 

Reinforced panels:

Reinforced panels are marked after autoclaving and demoulding, with stamp code containing information about the type of product, density, permissible load, dimensions, batch number and order number. An arrow indicating the top side of the panels will be marked at one end of the floor/roof slabs and lintels.

The following abbreviations are used for the types of product:

Abbrev. Meaning
WV Vertical Wall Panels
WH Horizontal Wall Panels
WP Partition Wall Panels
WF Fluted Wall Panels
RS Roof Slabs
FS Floor Slabs
LW Panel-Type Lintels
LA Arch-Type Lintels
LB Box-Type Lintels
B Blocks

Density 5 – denotes nominal dry density of 550 kg/m3 for both blocks and reinforced panels.
Density 4 – denotes nominal dry density of 450 kg/m3 for Hordi blocks.

Permissible load – Indicates service load in kg/m2 for walls and slabs or kg/lm in case of lintels.


Handling, Shipping and Storage


Siporex products are designed to resist normal handling and transport. Siporex blocks should be handled by forklifts and/or cranes with appropriate straps to avoid damage to the material.

Siporex materials are shipped by trucks or flat-bed trailers and can be transported by road, train and by sea for international projects.

They have unlimited storage stability, provided that they are not exposed to extreme conditions. They must be supported by properly placed bearers and stored in such a way that they cannot absorb water from the ground or be splashed with sea water. Siporex is an inorganic material and is not affected by termites and other insects.

Siporex Blocks:
Bundles of blocks (60 cm high) are stored on wooden pallets. Each pallet can be stored with up to 3 bundles of blocks (180 cm high). At the storage area, the floor should be level to avoid tilting of stocks. Stocks of blocks can easily withstand 3 pallets with 3 bundles each of Siporex blocks.

Reinforced Panels:
On the ground, the stacks of reinforced panels shall be supported by wooden planks, one on each end, placed approximately one fourth of the length from the ends.
In transporting, the stacks are tied by strapping at both ends, protected with plastic angles.