African Union Peace & Security Building

Project: African Union Peace and Security Building

Location: Addis Ababa

Implementing Agency: giz

Flintstone engineering

Ethio China Road Ave.

Addis Ababa, Sub City Cherkos, Kebele 03

PO Box 559/1110, Ethiopia

9 / 2 0 / 2 0 1 1

Date:21th February 2012

Work Methodology for prefabricated parapet construction

African union Peace & security building

Contents1. Scope of Methodology............................................................................................................................2

2. Column Reinforcement bar...................................................................................................................2

3. Column shuttering...................................................................................................................................3

4. Concrete Placing.......................................................................................................................................4

Labor Arrangement.........................................................................................................................................5

5. Schedule......................................................................................................................................................5

A U - P S B P a g e | 1

African union Peace & security building

1. Scope of Methodologyo This method statement relates to the construction of precast concrete parapet

construction and assembly work. o It shall mainly cover the processes related to the mass production and

assembly of standard diagonal parapet sections of a standard angle of inclination 780 and 800

o

2. Prefabrication

2.1 formwork productiono The AU-PSB Building has a sloped façade parapet on the west and south sides

of the building. This sloped façade is one of the major architectural significant features of the building.

o The sloped façade shall start from the slab above the first floor o The 50ml is the 810 slope (South Direction ) and the 44ml is the 780 slopes

(West direction)

o Concrete column heights to be cast at once may rich from 4.60m to 10.40m up to the bottom of ground floor beams. o 14.2 tons of reinforcement bars shall be fixed to ground floor circular columns.o The Ground floor wall rebar quantity is around 92 tons. o The rebar Overlap length shall not be less than 96cm for the main bars.o The rebar work shall continue to be done is 2 shifts.

A U - P S B P a g e | 2

African union Peace & security building

3. Column shuttering

There are around 39 circular columns in ground floor with a diamter as shown below,

o In order to finish the casting in one month, with the limited circular formwork available on site, it is a must to cast 5 columns of dia. 50cm columns in one week of time.

o Since the formwork on site are a maximum of 4m height we are forced to cut some of the column formworks which has a diameter less than 50cm and monolithically fix on the formworks of 4m height of the same diameter to get a full height of 6ml.

o Joints between two Half circle shall be sealed with silicon to avoid the outflow of cement paste during concrete casting.

o

o Bottom frame shall be prepared as shown above from a piece of plywood and fixed to the concrete floor slab so that later on the circular column formwork shall be precisely guided with it.

o After the inspection of the column reinforcement, the shuttering shall be closed.

o A bottom and top push and pull prop will be attached in a horizontal 900 angle and adjusted to get the vertical plumb.

o The circular formwork panel is painted with a release agent to avoid the bonding effect between the shuttering and concrete element. Sika Decoffre Mineral is the material that shall be used as a formwork releasing agent.

4. Concrete Placingo The ground floor wall concrete volume is about 47m3

o Casting shall start at the third week of February 2012o Concrete columns which have a diameter equal of less than 50cm shall be cast

in one layer while columns greater than 50cm shall be cast twice per floor height.

o The columns located in the plenary room shall be casted with C-40 concrete compressive strength.

A U - P S B P a g e | 3

African union Peace & security building

o Cement paste or cement rich concrete mix shall first be placed to a height of 1m where the reinforcement and starter bars are congested in order to avoid the honey comb due to outflow of concrete, or due to segregation effect.

o PVC casting pipes of diameter 160mm shall be used to place the concrete to the bottom of column sections.

o Pocket Vibrator hose of length greater than 6m shall be used for casting columns.

o Viberator hose shall be inserted in the columns and shall be removed out very slowly.

o A gauging rod shall be prepared from reinforcement bar so that to assist the mason not to fill in excess of the required height.

o A copy of Concrete Delivery ticket (concrete book) shall be delivered to giz office for each mix of concrete.

o Site arrangement shall be made for slump tests and concrete cube tests for quality assurance purposes according to the DIN Standard.

Labor Arrangement

1. Surveying Teamo 1 Surveyoro 1 Assistant Surveyoro 2 Daily Laborers

2. Cleaning Teamo 1 Labor with the Compressor machineo 3 Cleaners

3. Welding Teamo 2 Welderso 2 Daily Laborerso

4. Tower Crane Operatoro 3 Operatoro 1 Assistant Operatoro 1 Mechanic

5. Shuttering fixing crewo 6 carpenters

A U - P S B P a g e | 4

African union Peace & security building

o 8 Daily Laborerso General Foremano Foremano Group Leader

6. Concrete casting groupo 3 mason in concrete placingo 6 carpenters to check the shuttering in placeo 13 Daily Laborers

5. Schedule

o In order to finish the 39 columns within 15 days, we have to cast 3 columns in a day.

o For the 50cm diameter column, we shall cast 3 columns in two days gap.

A U - P S B P a g e | 5