Spencer Dock Hotel
Friday, 25th April 2008

What is believed to be the largest pour of its type in Ireland to date (2625 cubic metres) will begin on Friday 25th April when over half the raft basement slab is poured at the proposed Spencer Dock Hotel.

Information on the pour:
Total area of the hotel is 80m by 24 m = 1920 m2
Pour on 25-04-08 is 42m by 24m = 1008 m2 which is over half the complete hotel
Top of concrete is generally at -3.5m OD
Bottom of concrete in central section is at –6.8m OD
Therefore some parts of pour will be 3.3m deep but most will be 2.5 m deep
Predicted volume for 25-04-08 is 2625m3 of concrete including reinforcement and holding down bolts
The base of four lift shafts are incorporated in the pour
The base of this pour alone sits on 140No total piles - 50No 1200 diameter piles, 20No. 1050 diameter piles and 70No 900 diameter piles which go down up to a further 14m into the ground with embedment into rock
Reinforcement tonnage in this portion alone is well in excess of 850 tonne
The mats of steel are primarily 40mm diameter high tensile steel bars 12 m long – 4 mats of steel in the bottom, 4 mats of steel in the top with 2 intermediate layers of 16 mm diameter – note it took 7 men to place one of these bars at a time
There are 28 sets of holding down bolt frames varying in make up but some types have 12 56mm dia bolts 1600mm long to carry the load bearing columns which have 200 mm thick base plates
The 2625m3 concrete will be placed with 3No concrete pumps( with over 50m booms ) – 2 duty and 1 standby
Concrete supplied from Kilsaran from South Bank Ringsend and Tallaght, backup plants Lucan and Clonee
28 concrete trucks will deliver concrete at a rate of nearly 200m3 an hour peak time
70% GGBS is being used
The concrete is a flowable mix
Temperature is expected to reach 55C on day three in the centre of the pour
8 temperature monitors each taking readings at the top, middle and bottom of the concrete
slab will be insulated after finishing with layers of 75mm insulation and ply to prevent excessive heat loss and thermal gradients
start on site at 4pm 25-04-08 with a slow steady start to ensure bottom layers of concrete (up to 3.3m below) are poured and vibrated correctly to remove any entrained air and to get in and around the bottom reinforcement
finish on site is expected early evening on 26-04-08 pouring concrete
finishing to concrete will take a further 12 hours after pour then slab will be insulated