Assessment of wind-driven rain impact, related surface erosion and surface strength reduction of historic building materials

Building surface erosion is a common phenomenon observed on historic building facades due to wind-driven rain (WDR) impact. Recently, studies on climate change and the effect this might have on increased extreme rainfall events has renewed the scientific interest on determining the risk of accelerated erosive effects. Given the fact that WDR loads on building facades is proportional to rainfall and represents the main moisture source and erosive physical impact for building facades, an assessment method that quantifies the severity of erosion is the first step towards recommending remedial measures. The paper discusses the major factors escalating the gradual loss of surface material, considering value, hazard, vulnerability and exposure in order to examine the WDR drop impact on the aesthetic significance and the structural integrity of heritage buildings, within a parametric framework. The study investigates the effects of different size water drops, with different impact speeds on a range of masonry materials with different surface asperities and varying moisture absorption features, at various impact angles. For the relative quantification of the long-term surface erosion, straightforward and globally adaptable experiments are proposed based on site-specific climatic data and materials. Finally, strength decline of exposed sample units proves the strength-degrading effect of erosive WDR.

[1]  A. Cassie,et al.  Wettability of porous surfaces , 1944 .

[2]  S. Zaleski,et al.  Drop dynamics after impact on a solid wall: Theory and simulations , 2010 .

[3]  Anthony Geoffrey Kerali,et al.  Durability of compressed and cement-stabilised building blocks , 2001 .

[4]  An-Bang Wang,et al.  On some common features of drop impact on liquid surfaces , 2004 .

[5]  C. Jayasinghe,et al.  Compressive strength characteristics of cement stabilized rammed earth walls , 2007 .

[6]  Jan Carmeliet,et al.  Wind-driven rain on buildings facades: some perspectives , 2009 .

[7]  J. Carmeliet,et al.  Overview of three state-of-the-art wind-driven rain assessment models and comparison based on model theory , 2010 .

[8]  Omar Matar,et al.  Droplet spreading, imbibition and solidification on porous media , 2006, Journal of Fluid Mechanics.

[9]  Wolfgang Kron,et al.  Flood Risk = Hazard • Values • Vulnerability , 2005 .

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

[11]  D. Sivakumar,et al.  Impact of water drops onto the junction of a hydrophobic texture and a hydrophilic smooth surface , 2010 .

[12]  Peter Walker,et al.  The Measurement of the Carbonation Profile in Lime Mortars using a Drilling Resistance Measurement System , 2008 .

[13]  Christian Salles,et al.  Rain properties controlling soil splash detachment , 2000 .

[14]  Maureen E. Young.  Dampness penetration problems in granite buildings in Aberdeen, UK: Causes and remedies , 2007 .

[15]  Cliff I. Davidson,et al.  Erosion of limestone building surfaces caused by wind-driven rain: 1. Field measurements , 2004 .

[16]  Bernard J. Smith,et al.  A commentary on climate change, stone decay dynamics and the ‘greening’ of natural stone buildings: new perspectives on ‘deep wetting’ , 2011 .

[17]  Xishi Wang,et al.  Experimental study of water drop impact on wood surfaces , 2011 .

[18]  Matthew D. Collins,et al.  UK Climate Projections Science Report: Climate Change Projections , 2009 .

[19]  R. B. Rezaur,et al.  Measuring drop size distribution and kinetic energy of rainfall using a force transducer , 2000 .

[20]  K. A. Heathcote,et al.  Durability of earthwall buildings , 1995 .

[21]  G. Jenkins,et al.  The climate of the United Kingdom and recent trends , 2007 .

[22]  J. E. Oti,et al.  Engineering properties of unfired clay masonry bricks , 2009 .

[23]  M. B. Caroe,et al.  Wells Cathedral Conservation of Figure Sculptures, 1975-1984 , 1985 .

[24]  Cameron Tropea,et al.  On the Splashing Threshold of a Single Droplet Impacting onto Rough and Porous Surfaces , 2010 .

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

[26]  Staf Roels,et al.  Impact, absorption and evaporation of raindrops on building facades , 2009 .

[27]  C. Tropea,et al.  Outcomes from a drop impact on solid surfaces , 2001 .

[28]  M. A. Nearing,et al.  Measurement of force vs. time relations for waterdrop impact , 1986 .

[29]  Jean-Pierre Delplanque,et al.  The role of air entrainment on the outcome of drop impact on a solid surface , 2008 .

[30]  Giovanni G. Amoroso,et al.  Stone Decay and Conservation: Atmospheric Pollution, Cleaning, Consolidation and Protection , 1983 .

[31]  Hl Henk Schellen,et al.  Wind-driven rain on the facade of a monumental tower: numerical simulation, full-scale validation and sensitivity analysis , 2009 .

[32]  Kevan Aubrey Heathcote,et al.  An investigation into the erodibility of earth wall units , 2002 .

[33]  William F. Adler,et al.  Waterdrop impact modeling , 1995 .

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

[35]  Fernando M.A. Henriques,et al.  Proceedings of the 7th International Congress on Deterioration and Conservation of Stone , 1992 .

[36]  R P J McCullagh.  Excavations at Sueno's Stone, Forres, Moray , 1995 .

[37]  R. N. Wenzel.  RESISTANCE OF SOLID SURFACES TO WETTING BY WATER , 1936 .

[38]  A. Yarin.  Drop Impact Dynamics: Splashing, Spreading, Receding, Bouncing ... , 2006 .

[39]  Marco Marengo,et al.  Drop collisions with simple and complex surfaces , 2011 .

[40]  J. Carmeliet,et al.  A review of wind-driven rain research in building science , 2004 .

[41]  Edmund C.C Choi.  Wind-driven rain and driving rain coefficient during thunderstorms and non-thunderstorms , 2001 .

[42]  Rosemarie Helmerich,et al.  CHEF - Cultural heritage protection against flooding , 2011 .

[43]  Covadonga Palencia,et al.  Rain events on 22 October 2006 in León (Spain): Drop size spectra , 2009 .

[44]  Dongqing Li,et al.  Liquid drop spreading on solid surfaces at low impact speeds , 2000 .

[45]  Stephan Borrmann,et al.  Shapes and oscillations of falling raindrops — A review , 2010 .

[46]  A. Best,et al.  The size distribution of raindrops , 1950 .

[47]  C. M. Grossi,et al.  Mapping the impact of climate change on surface recession of carbonate buildings in Europe. , 2009, The Science of the total environment.

[48]  C. T. Avedisian,et al.  Observations of droplet impingement on a ceramic porous surface , 1992 .

[49]  Marco Marengo,et al.  Time evolution of liquid drop impact onto solid, dry surfaces , 2002 .

[50]  C. Hall.  Water movement in porous building materials—IV. The initial surface absorption and the sorptivity , 1981 .