Longevity of Borehole and Shaft Sealing Materials: Characterization of Ancient Cement Based Building Materials

Langton, C.A.; Roy, Della M.

doi:10.1557/proc-26-543

Cited by 29 publications

(17 citation statements)

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“…An Imperial Roman concrete prototype, with pyroclastic rock as both mortar pozzolan and conglomeratic coarse aggregate, would potentially add fracture toughness and self-healing properties to specialty sealing materials (58) and constructions in areas of moderate seismic activity. Variations in the mineralogical, granulometric, and chemical compositions of a given pyroclastic deposit would have to be thoroughly understood, however, before it could satisfy quality control specifications for stability and safety considerations in modern applications.…”

Section: Discussionmentioning

confidence: 99%

Mechanical resilience and cementitious processes in Imperial Roman architectural mortar

Jackson¹,

Landis

Brune

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

173

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The pyroclastic aggregate concrete of Trajan's Markets (110 CE), now Museo Fori Imperiali in Rome, has absorbed energy from seismic ground shaking and long-term foundation settlement for nearly two millenia while remaining largely intact at the structural scale. The scientific basis of this exceptional service record is explored through computed tomography of fracture surfaces and synchroton X-ray microdiffraction analyses of a reproduction of the standardized hydrated lime-volcanic ash mortar that binds decimeter-sized tuff and brick aggregate in the conglomeratic concrete. The mortar reproduction gains fracture toughness over 180 d through progressive coalescence of calcium-aluminum-silicate-hydrate (C-A-S-H) cementing binder with Ca/(Si+Al) ≈ 0.8-0.9 and crystallization of strätlingite and siliceous hydrogarnet (katoite) at ≥90 d, after pozzolanic consumption of hydrated lime was complete. Platey strät-lingite crystals toughen interfacial zones along scoria perimeters and impede macroscale propagation of crack segments. In the 1,900-y-old mortar, C-A-S-H has low Ca/(Si+Al) ≈ 0.45-0.75. Dense clusters of 2-to 30-μm strätlingite plates further reinforce interfacial zones, the weakest link of modern cement-based concrete, and the cementitious matrix. These crystals formed during long-term autogeneous reaction of dissolved calcite from lime and the alkali-rich scoriae groundmass, clay mineral (halloysite), and zeolite (phillipsite and chabazite) surface textures from the Pozzolane Rosse pyroclastic flow, erupted from the nearby Alban Hills volcano. The clastsupported conglomeratic fabric of the concrete presents further resistance to fracture propagation at the structural scale.Roman concrete | volcanic ash mortar | fracture toughness | interfacial zone | strätlingite

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Section: Discussionmentioning

confidence: 99%

Mechanical resilience and cementitious processes in Imperial Roman architectural mortar

Jackson¹,

Landis

Brune

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

173

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“…Further to the data in the literature (1)(2)(3)(4)(5)(6)(7), the excellent durability of many known ancient structures may be attributed essentially to the mineralogy of their cements, and specifically to their large store of alkaline metal phases (alkaline aluminosilicate hydrates similar in composition to natural zeolites) that co-exist with calcium silicate hydrate phases.…”

Section: Introductionmentioning

confidence: 89%

A review on alkaline activation: new analytical perspectives

et al. 2014

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For many years now the idea of including alkalis in a Portland cement matrix has been regarded as a daft or inexcusably erroneous proposition: despite its absurdity, that opinion has been widely accepted as a basic premise by the scientific and technical community working in the area of the chemistry of cement. In 1957 Glukhovsky proposed a working hypothesis in which he established a close relationship between alkalis and cementitious materials. That hypothesis has become consolidated and has served as a basis for developing a new type of binders, initially called "alkaline cements". The present paper reviews the most significant theoretical interpretations of the role played by alkalis in the formation of the "stony" structure of cement. It ends with a broad overview of the versatility of this type of materials for industrial applications and a discussion of the possibility of building on the existing legislation to meet the need for the future regulation of alkaline cement and concrete manufacture. RESUMEN: Activación alcalina: Revisión y nuevas perspectivas de análisis.Hace algunos años, la sola idea de la presencia de álcalis en una matriz de cemento Portland se consideraba casi como una aberración, o como un error imperdonable; convirtiéndose en un postulado básico (absurdo) ampliamente aceptado por la comunidad científica y técnica vinculada a la química de los cementos. En 1957 Glukhovsky propuso una hipótesis en la que se establecía una estrecha relación entre los álcalis y los materiales cementantes. Hoy día nadie duda de que dicha hipótesis ha servido de base para el desarrollo de una nueva clase de materiales cementantes: "cementos alcalinos". En el presente trabajo se hace una revisión sobre los aspectos teóricos más relevantes del papel de los álcalis en la formación de estos conglomerantes. También se da una visión genérica de su versatilidad, desarrollo industrial y estado de la normativa actual para regular en el futuro la fabricación de cementos y hormigones alcalinos.

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“…These investigations include the characterizationstudies of archaeological cementitious materials by Langton (1983, 1989), Langton and Roy (1984), and Jiang and Roy (1994). Roy and Langton (1983) and Langton and Roy (1984) investigated the long-term stability of cement in plasters, mortars, andlor concrete from ,the perspective of their use as borehole plugging and shaft sealing materials in a radioactive waste disposal facility. They examined approximately 100 samples of ancient materials dated fiom 1,400 to 3,000 years old from Italy, Greece, Crete, and Cyprus.…”

Section: C42 Physical Stability Studiesmentioning

confidence: 99%

Effects on radionuclide concentrations by cement/ground-water interactions in support of performance assessment of low-level radioactive waste disposal facilities

Krupka¹,

Serne²

1998

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C o p k r o f h b r t r y~m d r t n d v d r u n d h 8~m m r h t h . N R C~~r AbstractThe U.S. Nuclear Regulatory Commission (NRC) is developing a technical position document that provides guidance regarding the performance assessment of low-level radioactive waste (LLW) disposal facilities. This guidance includes considerations associated with the chemical environment of the vault disposal system and the effects this system may have on the release and mobility of radionuclides. Because the disposal system will contain cementitious materials as structural, waste form, andor bacld'ill materials, the geochemical properties of pore waters buffered by reactions with cement will be very different from those waters associated with the local soil and geology. This environment therefore needs to be considered within the source term calculations if credit is taken for solubility limits andor distribution coefficients for -dissolved radionuclide concentrqtions within disposal units. Geochemical modeling may be used to assess potential chemical conditions in concrete vault disposal units and associated effects on aqueous speciation, solubilities, and sorption of radionuclides that are released from the waste form.In support of NRC7s development of this technical position, two literature reviews were done on information related to the chemical environments associated with the interaction of water with cementitious materials. One review was conducted on methods and associated solid-phase assemblages used to model the composition of pore water resulting from reaction with cementitious materials used in a disposal vault. This literature review also included related information on experimental studies of cemendwater systems, natural analogue studies of cement and concrete, and radionuclide solubilities experimentally determined in cement pore fluids.Based on the results of .this review, geochemical modeling was used to demonstrate the calculation of conservative maximum concentrations for dissolved americium, neptunium, nickel, plutonium, radium, strontium, thorium, and uranium with respect to key geochemical input parameters for two ground-water environments associated with the disposal system. These environments include 1) a cement buffered system, wherein the leachate pH is controlled at values above 10 by the effective buffering capacity of the concrete; and 2) a ground-water buffered system, wherein the leachate pH and related solution parameters are dominated by the local ground-water system.Another literature review was completed on the available data for the sorption potential of selected LLW radionuclides onto "fresh" cement/concretewhere the expected pH of the cement pore waters will equal or exceed 10. The review included data for the radionuclides americium, inorganic carbon, chlorine, iodine, lanthanide elements, niobium, nickel, neptunium, plutonium, radium, strontium, technetium, thorium, and uranium. Based on information gleaned from the literature, a database was developed of preferred minimum distribution coeff...

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Longevity of Borehole and Shaft Sealing Materials: Characterization of Ancient Cement Based Building Materials

Cited by 29 publications

References 1 publication

Mechanical resilience and cementitious processes in Imperial Roman architectural mortar

Mechanical resilience and cementitious processes in Imperial Roman architectural mortar

A review on alkaline activation: new analytical perspectives

Effects on radionuclide concentrations by cement/ground-water interactions in support of performance assessment of low-level radioactive waste disposal facilities

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