Research Paper: Granular interface over pyritic subgrade

Czerewko and Cross (AECOM) have published a paper on the use of a granular construction interface to separate road pavements from underlying pyritic subgrade. The authors consider case studies and the implications for road construction where such an interface has and has not been used.

The paper, titled “Benefits of a granular interface over pyritic subgrades” follows a prior case history publication by M. Czerewko on the construction of the A46, whereby pyritic subgrade extended over much of the road scheme:

Czerewko, M.A., Cross, S.A., Dimelow, P.G., and Saadvandi, A. (2011). Assessment of pyritic Lower Lias mudrocks for earthworks.… Read the rest

Case Study: Pyrite in “Chinese Drywall”

Chinese drywall

According to the Wikipedia page on the topic, Chinese Drywall refers to “…an environmental health issue involving defective drywall manufactured in China and imported to the United States starting in 2001”. Drywall is also known as plasterboard and is comprised predominantly of gypsum plaster.

problems and potential cause

According to the Construction Lawyers Blog:

“Most of the homes that have Chinese drywall were built between 2001 and 2008”

“Testing of Chinese drywall has found unusually high instances of pyrite.”

“There is speculation that the pyrite oxidation results in sulfur compounds being released by the drywall during periods of high heat and humidity.”

“Reports show that homeowners typically complain of corroding copper in their homes, and a rotten egg odor emanating from copper surfaces that, in turn, turn black and exhibit a powdery ash type substance. 

Read the rest

HomeBond’s Repudiation of Purchasers’ Claims

Homebond’s repudiation of purchasers’ claims – was it lawful?

Joseph Tyrrell (FCII, FCILA, FUEDI-ELAE), an insurance claims expert from Dublin, has published an extensive report on HomeBond’s repudiation of purchasers’ claims under the Major Defects Warranty in the HomeBond Agreement for Damage by Pyritic Heave.

report executive summary

In the report summary, Joseph Tyrrell writes:

“Following a wide-ranging investigation, I am satisfied that HomeBond’s rejection of hundreds of its warranty-holders’ claims was invalid, for reasons which I have examined in detail in the main body of this report…”

“It is astonishing, to my mind, that no one in authority appears to have looked closely at the reasons given for wrongfully turning down so many Purchasers’ claims, but it seems that this is what happened and that HomeBond has thus far got away with its shameful behaviour.

Read the rest

Sinkholes: Buried alive – Documentary featuring gypsum dissolution

Sinkholes documentary

Tonight, at 20:00 GMT on Channel 5 (UK), the documentary “Sinkholes: Buried Alive” will feature the hazards associated with the dissolution of ground materials, including gypsum. The documentary summary is below:

“Sinkholes can occur gradually when the surface subsides into bowl shaped depressions or suddenly when the ground gives way. These geological hazards have swallowed highways, apartment buildings, horses, camels, even golfers, with monster-size holes cracking the earth from Siberia to Louisiana. Filled with compelling eyewitness video of dramatic collapses, and following scientists as they explore the underlying forces behind these natural disasters, this documentary travels the globe to investigate what it’s like to have your world vanish beneath your feet.”

The documentary will focus mainly on limestone sinkholes in Florida and a major salt-mining induced sinkhole at Bayou Corne, Louisiana.… Read the rest

BS 5930:2015: new guidance on sulfur-species

BS 5930:2015

On 31 July 2015, BS 5930:2015 “Code of practice for ground investigations” was published, replacing the former standard, BS 5930:1999+A2:2010 (Code of practice for site investigations). The BSI website states that:

“BS 5930:2015 deals with the investigation of sites in order to assess their suitability for construction and to identify the characteristics of a site that affect the design and construction of the project.  It also considers related issues including the environment and the security of adjacent land and property.”

“This is a full revision of the standard and introduces some principal changes…” [including] “…Compliance with BS EN 1997-1 and BS EN 1997-2 and related test standards…” [and] “…New information on geophysical surveying and ground testing and updated guidance on desk studies, field reconnaissance, ground investigations on contaminated ground and ground affected by voids.”

Guidance on sulfur-species

BS 5930:2015 provides considerable additional guidance on the presence and assessment of sulfur-species in geological materials compared to the 1999 version.… Read the rest

Uses of pyrite: historic and modern

Pyrite is the cause of many problems in engineering, but in the past (and more recently) it has found a number of uses. This post considers some of the historical and present uses of pyrite. Links to references are included where further information can be found. This post is frequently updated with new technologies, so please check back regularly.

Historic uses of pyrite

Ignition source

In the 16-17th centuries, pyrite was used as a source of ignition in early guns. According to (Willbanks 2004), the “wheel lock” weapon was invented in Germany around 1517.… Read the rest

New summaries of Thaumasite and Mundic problems

NEW summaries and case history pages added

Thaumasite and Mundic problems

Two new summaries/case history pages have been added to the website. These summaries concern the UK Thaumasite and Mundic problems. The pages are work-in-progress so do please check back for updates. Click the links below to find out more:

1. The UK Thaumasite problem

The summary details the UK problems associated with thaumasite. The summary includes notes on:

  • Cases of thaumasite sulfate attack in the UK (mostly on foundations of the M5 motorway bridge structures)
  • Publications, research and conferences relating to thaumasite, dating back to 1985
  • On-going remediation of bridge structures in Gloucestershire
  • Technical documents and standards

2.… Read the rest

Pyrite Resolution Board report: 2014

Pyrite Resolution Board Report 2014

The Pyrite Resolution Board report (for 2014) was published on 17th June 2015. The report PDF can be found on the Pyrite Resolution Board website, or by clicking this link.

Applications Summary (END of 2014)

The PRB first annual report provides a summary of applications to the Board. Photographs of typical damage and the remediation process are included within the report. At the end of 2014, the applications were as follows:

620 applications in total
145 applications at Validation (including 6 refused applications)
171 applications Validated, at Verification
3 applications Verified and awaiting decision on inclusion
301 applications Included in scheme
106 applications in Planning/Scheduling
190 applications at Specification and Tender Preparation stage
0 applications in Remediation
5 applications Remediated

expenditure

The total expenditure reported for 2014 was reported as €796,969, with the following breakdown:
IT System Setup €72,320
Engineers €145,380 (€306,722 outstanding at end of 2014)
Works Contractors €144,371 (€3,701 outstanding at end of 2014)
Homeowner’s Payments €142,756
Administration & Overheads €292,142
The above can also be considered in terms of proportions of the whole expenditure (own calculations, not those of the PRB):
IT System Setup (9 %)
Engineers (18 %)
Works Contractors (18 %)
Homeowner’s Payments (18 %)
Administration & Overheads (37 %)
An additional €1,663,224 is possible for future payments “…in respect of the 301 dwellings included in the Scheme in 2014 for the Building Condition Assessment, alternative accommodation and storage…”

legal proceedings

The PRB report states that “…legal proceedings by the PRB against a developer in respect of 17 dwellings have commenced and it is anticipated that others will follow.Read the rest

Research paper: undrained shear strength of sulfide soils

sulfide Soils: undrained shear strength

Bo Westerberg (Swedish Geotechnical Institute), Rasmus Muller and Stefan Larsson (KTH Royal Institute of Technology, Stockholm) have published a paper on the determination of undrained shear strength of coastal sulfide soils in the Gulf of Bothnia.

The paper, titled “Evaluation of undrained shear strength of Swedish fine-grained sulphide soils” adds to previous research by the authors on the sulfide-bearing soils of Sweden and Finland. The full abstract from Engineering Geology is shown below. Click here to read the abstract on the Science Direct website and access the paper.

Abstract

“In Swedish practice, there is a long tradition of evaluating undrained shear strength from fall-cone tests and field vane tests.
Read the rest

New Standard on building materials: BS 7543:2015

BS 7543:2015 published

BSI has published updated guidance on the durability of buildings. BS 7543:2015, titled “Guide to durability of buildings and building elements, products and components” replaces BS 7543:2003 and came into effect on 30th April 2015 as the third edition of the standard. The scope for the Standard states that it “…gives guidance on durability, design life and predicted service life of buildings, constructed assets and their parts. It applies to both new and existing buildings.”

The document quotes that it “…takes the form of guidance and recommendations. It should not be quoted as if it were a specification or a code of practice and claims of compliance cannot be made to it.”

Aspects of BS7543:2015 relevant to sulfur-species

The following paragraphs, quoted from BS7543:2015 are relevant to sulfur-species in building materials or their effects on building materials.… Read the rest