Mechanical and Microstructural Investigation of Geopolymer Concrete Incorporating Recycled Waste Plastic Aggregate.

The effective use of waste materials is one of the key drivers in ensuring sustainability within the construction industry. This paper investigates the viability and efficacy of sustainably incorporating a polylactic acid-type plastic (WP) as a 10 mm natural coarse aggregate (NA) replacement in geopolymer concrete. Two types of concrete (ordinary Portland cement-OPC and geopolymer) were produced for completeness using a concrete formulation ratio of 1:2:3.

The use of portable XRF as a forensic geoscience non-destructive trace evidence tool for environmental and criminal investigations.

Hand-held, portable X-Ray fluorescence instruments (pXRF) provide a means of rapid, in-situ chemical characterisation that has considerable application as a rapid trace evidence characterisation tool in forensic geoscience. This study presents both a control test study which demonstrates optimisation of the data collection process, alongside a range of individual forensic case studies, including heavy metal contamination, conflict archaeology, forensic soil characterisation, and verification of human remains, which together validate the technique and provide some comparison between field-based and laboratory-based pXRF applications. Results highlight the time-efficiency and cost-effectiveness of in-situ, field-based pXRF analyses for material characterisation when compared with other trace evidence methods.

Petrological and geochemical characterisation of the sarsen stones at Stonehenge.

Little is known of the properties of the sarsen stones (or silcretes) that comprise the main architecture of Stonehenge. The only studies of rock struck from the monument date from the 19th century, while 20th century investigations have focussed on excavated debris without demonstrating a link to specific megaliths. Here, we present the first comprehensive analysis of sarsen samples taken directly from a Stonehenge megalith (Stone 58, in the centrally placed trilithon horseshoe).

Ancient DNA, lipid biomarkers and palaeoecological evidence reveals construction and life on early medieval lake settlements.

Direct evidence of ancient human occupation is typically established through archaeological excavation. Excavations are costly and destructive, and practically impossible in some lake and wetland environments. We present here an alternative approach, providing direct evidence from lake sediments using DNA metabarcoding, steroid lipid biomarkers (bile acids) and from traditional environmental analyses.

Identification and analysis of man-made geological product particles to aid forensic investigation of provenance in the built environment.

Small (sub-mm) fragments of construction materials derived from geological products are common components of soil and dust samples from urban and industrial environments. These particles increase the complexity of a soil through the admixture of man-made materials with natural minerals within the soil matrix. One application of such indicators is in nuclear security investigations, where there is a requirement to determine the origin and process history of a nuclear material discovered outside of regulatory control.

The Search for "Fred": An Unusual Vertical Burial Case.

Police witness intelligence stated a murdered adult male "Fred" had been vertically buried in wooded hilly terrain 30 years ago in the Midlands, U.K. Conventional search methods were unsuccessful; therefore, the police requested a geophysical investigation to be undertaken to determine whether "Fred" could be detected.

Testing the efficiency of soil recovery from clothing for analysis by SEM-EDS.

Soil forensics is widely used to test associations between questioned samples and known locations. Improvements in analytical techniques mean that increasingly small amounts of soil can be analysed. This is particularly important as individual traces of soil relate to individual geographical locations and need to be analysed separately.

Composition and abundance of particles present on "powder-free" examination gloves.

Seven widely available brands of powder free nitrile gloves, commonly used in forensic laboratories during the handling of exhibits were examined. Samples were collected from the outer surfaces of the gloves and the particle types present were characterised using automated mineral analysis. Particles less than 10μm in diameter are abundant on the surface of all of the gloves examined.

Geochemistry and mineralogy of arsenic in mine wastes and stream sediments in a historic metal mining area in the UK.

Mining generates large amounts of waste which may contain potentially toxic elements (PTE), which, if released into the wider environment, can cause air, water and soil pollution long after mining operations have ceased. The fate and toxicological impact of PTEs are determined by their partitioning and speciation and in this study, the concentrations and mineralogy of arsenic in mine wastes and stream sediments in a former metal mining area of the UK are investigated. Pseudo-total (aqua-regia extractable) arsenic concentrations in all samples from the mining area exceeded background and guideline values by 1-5 orders of magnitude, with a maximum concentration in mine wastes of 1.

Automated mineralogical analysis of PM10: new parameters for assessing PM toxicity.

This work provides the first automated mineralogical/phase assessment of urban airborne PM10 and a new method for determining particle surface mineralogy (PSM), which is a major control on PM toxicity in the lung. PM10 was analyzed on a TEOM filter (Aug.-Sept.