Erosion of limestone building surfaces caused by wind-driven rain: 1. Field measurements

Abstract Complex patterns of discoloration are often seen on the surfaces of stone buildings in urban areas. These patterns reflect interactions between atmospheric pollutants, the surface layers of stone, and wind-driven rain that can erode the surface. This first paper in a two-paper series presents field measurements of wind-driven rain on a tall limestone building. The volume of driving rain on the building wall was measured at 16 locations over a 21-month period, and meteorological data were recorded for the same period. Analysis of data from 94 rain events suggests that wind-driven rain is strongly affected by rainfall intensity, wind speed, wind direction and measurement location. The five locations with driving rain volumes 4 l over this period are characterized by heavily soiled walls, while the two locations with driving rain volumes > 8 l are characterized by white, eroded walls. The remaining nine locations have driving rain volumes in the range 4– 8 l and varying amounts of soiling, with no clear relationship between these two variables. It is hypothesized that variation in raindrop momentum, which was not measured, is partially responsible for surface erosion and thus removal of soiling in this last category.

[1]  Edmund C.C Choi,et al.  Simulation of wind-driven-rain around a building , 1993 .

[2]  CHANGES IN SOILING PATTERNS OVER TIME ON THE CATHEDRAL OF LEARNING , 2003 .

[3]  D. Paterson,et al.  Computation of rain falling on a tall rectangular building , 1997 .

[4]  Horia Hangan,et al.  Wind-driven rain studies. A C-FD-E approach , 1999 .

[5]  van Fjr Fabien Mook,et al.  Driving rain on building envelopes , 2003 .

[6]  Cliff I. Davidson,et al.  Erosion of limestone building surfaces caused by wind-driven rain: 2. Numerical modeling , 2004 .

[7]  S. Sherwood,et al.  Laboratory study of SO2 dry deposition on limestone and marble: Effects of humidity and surface variables , 1995 .

[8]  Jan Carmeliet,et al.  Driving Rain on Building Envelopes— II. Representative Experimental Data for Driving Rain Estimation , 2000 .

[9]  Wei Tang,et al.  Soiling patterns on a tall limestone building: Changes over 60 years , 2000 .

[10]  Jacob A. Wisse,et al.  COMPUTER SIMULATION OF DRIVING RAIN ON BUILDING ENVELOPES , 1997 .

[11]  Jan Carmeliet,et al.  Driving Rain on Building Envelopes- I. Numerical Estimation and Full-Scale Experimental Verification , 2000 .

[12]  Sandrine Anquetin,et al.  Eulero-Lagrangian simulation of raindrop trajectories and impacts within the urban canopy , 1995 .

[13]  Vicken Etyemezian,et al.  Impingement of rain drops on a tall building , 2000 .

[14]  George V. Hadjisophocleous,et al.  Wind-driven rain distributions on two buildings , 1997 .

[15]  Jan Rosvall,et al.  Air Pollution and Conservation: Safeguarding Our Architectural Heritage , 1989 .

[16]  C. Davidson,et al.  VERTICAL GRADIENTS OF POLLUTANT CONCENTRATIONS AND DEPOSITION FLUXES ON A TALL LIMESTONE BUILDING , 1998 .