Creative Thinking in Precast Concrete

Eurocodes Roger Pope writes: Following Joe Locke’s letter published on 5 September 2000, you raised several questions about the impact of Eurocodes on design. My response to your queries based on my experience as an active player in the process concerning Eurocodes 0,1,3 and 4 is as follows: (1) Very few complete trial designs were ever undertaken using solely the ENV versions of the Eurocodes. Nearly all experience at ENV stage was with the NAD version in each country, often with pre-existing national loading codes not the actions specified in ENV 1991. As the NADs had been ‘calibrated’ to give the same design outcomes as pre-existing national codes it was hardly a surprise if trial designs undertaken with the ENV and NAD together resulted in design outcomes similar to that from pre-existing national codes! As an example, the UK NAD for ENV 1993-1-1 reduced the gamma factor for steel to 1.05 from a boxed value of 1.1 which eliminated 5% of the uncompetitiveness in the bare ENV.

This paper describes the civil work involved in the demolition of Tsing Yi Power Station in Hong Kong, during 1998. The work included the use of explosives to safely demolish the five, up to 150m-tall, reinforced concrete chimneys. This was one of the first and largest uses of explosives in demolition in Hong Kong. Demolition methods adopted in Hong Kong and the UK are compared and contrasted. T.J. Dishman

Eighteen large-scale reinforced concrete columns, with concrete compressive strength (fcu) of 55.24N/mm² or 76.15N/mm², were tested under short-term loading. The effective-length-to-depth ratios Le/h) of the columns are 26.2,28.7 or 30.4, load-eccentricity-to-depth ratio (e/h) is 0.25 or 0.50, and steel ratio (p) is 3.35% or 5.24%. The experimental behaviour of the columns is presented and discussed. P.H. Chuang, S.K. Kong and Emeritus Professor F. K. Kong