Repair of Silo, Raas

Application: Vishwas Waterproofing & Chemical INC

THE PROJECT : Shree Cement

Consultant : Holtec

Shree Cement is constructing new manufacturing unit at Raas having RM silo.

Problem :

Due to early pouring and early lifting of slip arrangements in construction, honeycombing found in constructed area and found very low strength in concrete.

CHALLENGE & SOLUTIONA big challenge was to provide strength in honeycombing area more than concrete grade in a short time period and as per technical requirements Fosroc team able to provide solution for proper repairing after getting approval from consultant.

A good applicator having sufficient equipment and technical team engaged to work in a short time at a height above 50 mtr.

Method StatementSurface Preparation

Chipping off the existing loose concrete. Cleaning the surface from dust, mortar splashes loose materials etc. to get a sound concrete surface. Clean the prepared surface with fresh clean water.

BONDING OLD & NEW CONCRETE / MORTAR

Wire brush the surface to remove laitance, loose particles etc., weak concrete / mortar surfaces should be removed totally by chiseling to get a sound surface.

Cleaning the surface with wire and nylon brushes.

Brush application of bonding agent Nitobond AR for Renderoc S2 and Nitobond EP for Renderoc RG.

PATCH REPAIRS TO STRUCTURAL MEMBERS 

Applying bonding coat Nitobond AR in the filling the same with Renderoc S2 a two component Pre Packed Polymer Modified Cementitious mortar.

Apply one full coat of Nitobond AR on the chipped area and apply Renderoc S2, a two component Pre Packed Polymer Modified Cementitious mortar. The mortar can be applied up to 20mm thickness at a time. To achieve more thickness apply a coat of Nitobond AR after 10 hours of proposed setting time of material and apply of Renderoc S2. Applying Renderoc RG, a low permeable, free flow, non-shrink, and self-compacting micro concrete of grade M45 in area where thickness is more than 40 mm after application of Bonding Agent Nitobond EP. For thickness more than 100mm, repair should be done with Renderoc RG mixed with graded coarse aggregates of maximum size 12mm in the ratio 1:0.75(by weight).The final & finished surface shall be saturated cured by continuous sprinkling of water on the surface.

Injection Grouting

Drill holes of suitable depth to fix aluminum nozzles of 12 mm dia in wall surface prior to repairing of surface. Spacing of holes shall be varied from 300 mm c/c to 350mm c/c. The Nozzles can also be plugged with Renderoc plug. Inject suitable grouting material into the nozzles at a pressure of 2.5 kg/cm2. The pressure should be maintained at least for 5 minutes. The injection process incase of vertical members should start from the lower most elevation to the highest. After the injection grouting process the extra length of the nozzles should be cut and finished flush with the concrete surface. In case of see through cracks, the grooves should be cut on the opposite side also and shall be filled with Renderoc Plug, to prevent leaking of grout.

 

THE BENEFITS

Fosroc solution has fulfilled customer requirements in both aspects. Experienced applicator team of Fosroc completed project timely with good quality of workmanship.

Honeycombing of structure

 

Silo after lifting slip forms 

Repairing with Renderoc RG

Project:- Repair of Silo, Raas

Application: Vishwas Waterproofing & Chemical INC

Repair in Silo

PRODUCTS

Renderoc S2

Nitobond AR

Conbextra EP10

Nitobond EP

Renderoc RG