Steel Bracket and Cast Concrete for Panel Rectification – Civil Engineering
1.0 SCOPE
• The purpose and scope of this method of statement is to provide the work methods, guidelines, and quality requirements for the rectification of the panel 5514-EIP-142.
• The rectification required shall be conducted to adjust the location of the:
✓ 2 corbels used as a base for the Double Tee slab.
✓ 2 E58 thickness plate with Dia 16 mm anchor bar.
2.0 REFERENCES:
• QDC Structure Calculation Note.
• The materials data Sheet.
• SAER-5803
3.0 MATERIALS/ EMBEDS
• Hilti Hit RE 500
• Sikagrout 114
• SS14E-102 Galvanized Steel Bracket.
• SS14E-101 galvanized Steel Plate.
• Galvanized M20 threaded bars Grade 87.
4.0 RESPONSIBILITIES
4.1
Site Manager shall be responsible in providing all necessary requirements at site such
as implementing all HSE requirement, manpower, materials and equipment to carry
out grouting activities as per schedule and as per project specification.
4.2 Quality Control Inspector shall be responsible to provide inspection documentation
such as RFI Notification to SAUDI ARAMCO. Ensure that grouting activities are being
carried out in compliance with the quality requirements from materials installation
activities.
4.3 HSE officer shall be responsible in carrying out safety measures such as preparation of
barricades and warning signs, work permits, etc.
5.0 PROCEDURE:
A. Rectification Of lhe Corbel:
5.1 All the area of involved concrete shall be identified, delimited and clearly marked out
prior to the commencement of the work.
5.2 The upper thickness of the corbels shall be chipped (20 mm) using hummer & chisel or
any other mechanical mean, after chipping, DT slab to be leveled by sim plate.
5.3
Drilling Machine shall be used to drill 6 holes (as shown in the attached sketch) with
diameter 22mm and depth 175mm.
5.4
Install M20 Threaded bars grade B7 in the location of the holes after filling the holes
with the epoxy chemical grout material (Hilti Hit RE 500) as per the manufacturer
recommendation in the technical catalogue.
5.5
Install the pre-fabricated steel bracket with stiffener (detail attached) and tie it to the
M20 threaded bar beside the corbel.
5.6
Fix a timber shuttering around the steel bracket and between corbel and steel plate
with the dimension shown in the attached shop drawing.
5.7 Non-Shrinkage grout material (Sikagrout-114) shall be casted to accommodate the
steel bracket.
5.8 After the initial sitting, the grout shall be cured as per the normal grouting practice
and Aramco specifications.
B. Rectification Of the E58 plate:
5.9 The area beside the (E-58) plate shall be clearly marked and identified with the
dimension of 350x 150 mm.
5.10 The marked area to be chipped (min. 16 mm) using hummer & chisel or any other
mechanical means.
5.11 The drilling Machine shall be used to drill 3 holes/plate (as shown in the attached
sketch) with diameter 20 mm and depth 175 mm.
5.12 M20 threaded bars shall be fixed in the location of the holes using epoxy chemical
grout material {Hilti Hit RE 500) in comply with the manufacturer recommendation in
the technical catalogue.
5.13 All loose or damaged concrete removed by suitable mechanical means until reaching
the sound concrete.
5.14 New Plate (350x150x12 mm) shall be installed beside the old one plug and side
welded to the plate itself and welded to the threaded bars.
5.15
It should be grouted by non-shrinkage grout material (Sikagrout 114)
5.8.2 Large Volume Repairs
This is a conventional method of repair and is advisable when the hand application or
spraying of the repair material is not feasible. In this type of repair, it is necessary to fix
some kind of formwork and fill it with concrete or grout. The method of preparing the
surface to be repaired is similar to that outlined in the patch repair. The defective
concrete must be removed so that the sound surfaces are exposed, and reinforcing steel
cleaned. Further, the surface to be repaired is cleaned with compressed air or water
immediately before the repair material is placed.
Formwork can be of a conventional rigid type, that either encloses the member to be
repaired, or is sealed to it at its edges, or it may consist of a flexible fabric, particularly
when grout is to be used. In grouted aggregate work, transparent panels are sometimes provided so that the progress of grouting can be watched. When mixed concrete is to be
used for the repair, provision must be made in the formwork for placing and
consolidating it. This means that the formwork has to be built up in stages as the work
proceeds or temporary openings can be provided in the forms through which access can
be obtained. All the joints between the sections of form work, and between the form work
and the existing concrete, must be sealed so as to prevent leakage, and the seal must be
maintained while the concrete is being consolidated. When the grout is used, some
provision must be made for venting air at the top as the grout rises.
When conventional concrete is utilized, the mix design will depend partly on the
dimensions and location of the repair. In components where there is an easy access for
placing and consolidating concrete and for which the thickness of the repair is 100 mm
or greater, a mix containing 20 mm maximum size aggregate is commonly necessary.
Addition of a superplasticizer may be necessary when consolidation is difficult. The
method of placing the concrete is similar to the new construction. Consolidation is best
achieved by internal vibration if there is access for vibrators. A limited amount of
external vibration may sometimes be required in conjunction with the internal vibration
to achieve complete consolidation.
5.8.3 Grouted Aggregate Repair
In this technique, coarse aggregate is filled into the spaces between the formwork and the
structure, and grout is then pumped in to fill the interstices between the aggregate
particles. The grout should be introduced at the lowest points of the formwork in order to
prevent the formation of air pockets. Injection tubes may be built into the formwork at
several levels if complete filling from the bottom would require too great an injection
pressure. Alternatively, injection pipes may be inserted from the top, reaching to the
bottom of the formwork, before the aggregate is placed. They are gradually withdrawn as
the level of grout rises. The aggregate grading must be such that the grout can flow freely
between the particles. This usually means that single-sized aggregate, generally 20 111111
or larger, should be used. This method is particularly suitable for underwater work and
for conditions where access is difficult.
Figure 5.8.2 is an illustration of the process of grouted aggregate repair.
5.8.4 Repair by Sprayed Concrete
This type of repair is suitable when the concrete cannot be formed by conventional
techniques. Jn this method of repair, a thin layer of high quality tine concrete is sprayed
on the surface of a structure to which it will bond strongly, restoring the protective cover
to the steel reinforcement, making good concrete that has spallcd or become abraded.
Shotcrete typically contains well-graded aggregates of 10 mm or less in size. The water
to cement ratio is usually 0.4 or less. Shotcrete can add strength lo weakened structures
damaged by chemicals, weather, fire, and overloading.
Modifications to the physical properties such as improved durability and adhesion to the
substrate are obtained by the use of admixtures, fiber reinforcement, and pozzalanie
materials. For example, superplasticizers and latex admixtures, when included in the mix,
reduce permeability and rebound, and improve adhesion to the substrate. Silica fume, in
Hilti HIT-RE 500 With HIT-VI HAS In Hammer Drilled Holes
SikaGrout 114 PDF Download – Cementitious, Shrinkage Compensated General Purpose Grout