Significance and Use

This guide provides information on methods that can assist the design and conservation professional in the selection and use of consolidants for stone.

Use of a consolidant should be considered only after developing a thorough understanding of all factors contributing to the deterioration of the stone. Such an understanding is best reached through a comprehensive survey of existing conditions, environment, and a definition of stone performance requirements, followed by laboratory analysis of the stone and its deterioration products. With this information it should be possible to identify the decay mechanisms and to develop a conservation plan for the stone. However, careful preliminary investigation may indicate that consolidation is an inappropriate treatment.

Decay Mechanisms A discussion of decay mechanisms is beyond the scope of this document; however, an understanding of decay mechanisms is critical to the evaluation and selection of appropriate treatment methods for stone including chemical consolidation. (See Bibliography for references.)

Stone consolidation should only be done as part of an overall conservation plan. Consolidating stone without resolving underlying problems contributing to its deterioration (such as rising damp or improper drainage) can cause the consolidation treatment to fail completely or to accelerate the rate of deterioration of the stone. The condition of the stone should be documented before and after treatment.

Past experience has shown that application of some consolidants may contribute to deterioration or create unanticipated problems. In some cases, it may not be appropriate to use a stone consolidant at all. Consolidation should be considered only after unsuccessful attempts to remove or modify degradation sources have been carried out.

Consideration should be given to the fact that consolidation of porous stone is an irreversible process. Consolidants that allow future retreatment should be selected if possible. For example, treatment of stone, particularly porous stone, with hydrophobic materials may not allow future retreatment with water-based consolidants.

No consolidant should be used that prevents or significantly retards water vapor migration through the stone.

1. Scope

1.1 This guide covers procedures for the selection and use of consolidants for preservation of stone.

1.2 When considering the use of stone consolidants, guidance from specialists experienced in stone conservation should be sought. Where work on features of artistic, architectural, cultural or historical importance is being considered, guidance from specialists in these fields should be sought. Historic preservation guidelines should be considered in planning the work.

1.3 This guide offers an organized collection of information or a series of options and does not recommend a specific course of action. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this guide may be applicable in all circumstances. This guide is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project's many unique aspects.

1.4 Limited description of tests are provided for informational purposes only. See the referenced standard for complete description.

1.5 The values stated in inch-pound unites are to be regarded as standard. The values given in parentheses are provided for information only and are not considered standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user to consult appropriate safety and health practices and determine the applicability of regulatory limitation prior to use.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

C88 Test Method for Soundness of Aggregates by Use of Sodium Sulfate or Magnesium Sulfate

C97 Test Methods for Absorption and Bulk Specific Gravity of Dimension Stone

C99 Test Method for Modulus of Rupture of Dimension Stone

C170 Test Method for Compressive Strength of Dimension Stone

C295 Guide for Petrographic Examination of Aggregates for Concrete

C418 Test Method for Abrasion Resistance of Concrete by Sandblasting

C779/C779M Test Method for Abrasion Resistance of Horizontal Concrete Surfaces

C880 Test Method for Flexural Strength of Dimension Stone

C1352 Test Method for Flexural Modulus of Elasticity of Dimension Stone

C1353 Test Method for Abrasion Resistance of Dimension Stone Subjected to Foot Traffic Using a Rotary Platform, Double-Head Abraser

D2244 Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates

D3960 Practice for Determining Volatile Organic Compound (VOC) Content of Paints and Related Coatings

E96/E96M Test Methods for Water Vapor Transmission of Materials

E179 Guide for Selection of Geometric Conditions for Measurement of Reflection and Transmission Properties of Materials

E284 Terminology of Appearance

E632 Practice for Developing Accelerated Tests to Aid Prediction of the Service Life of Building Components and Materials

G26 Practice for Operating Light-Exposure Apparatus (Xenon-Arc Type) With and Without Water for Exposure of Nonmetallic Materials (Discontinued 2001)

G53 Practice for Operating Light-and Water-Exposure Apparatus (Fluorescent UV-Condensation Type) for Exposure of Nonmetallic Materials

Keywords

Consolidants; Historic masonry/preservation; Performance--building materials/applications; Performance--environmental materials/applications; Stone; Stone consolidants

ICS Code

ICS Number Code 91.010.01 (Construction industry in general)

DOI: 10.1520/E2167-01R08

ASTM International is a member of CrossRef.

ASTM E2167