THE COMPOSITION AND CONSERVATION POTENTIAL OF THE CHARRED STRUCTURAL TIMBERS FROM THE HADDENHAM LONG BARROW, CAMBS
Author(s): C Caple, W Murray
This report defines in chemical and physical terms the waterlogged charred structural timber recovered from the excavation. It subsequently describes experiments to consolidate and so conserve this waterlogged char. Chapters describe the nature of the pyrolysis (charring process) and review the evidence for the physical and chemical changes that occur. SEM studies of the Haddenham char and comparative material together with light element analysis and ESR Spectrometry indicate a most likely scenario for the charring process. The water content of the waterlogged char and the elemental and crystalline nature of the mineral salts present within it were established. The now characterised char was subject to a series of experiments, to determine its physical condition consequent upon a series of different drying regimes; slow air drying, fast air drying, controlled (stepped RH) drying, solvent drying, freeze drying. Subsequent experiments tried a range of pretreatments. The resultsof these experiments established that the PEG 400/4000 pretreatment followed by controlled drying could effectively treat small samples to give visually acceptable results. However, none of the drying and consolidation treatments tested appeared likely to be able to successfully conserve the large pieces of char from Haddenham.
- Report Number:
- 115/1991
- Series:
- AML Reports (New Series)
- Pages:
- 107
- Keywords:
- Charcoal Plant Remains
