Esta guía para,oyecto y la ejecución de micropilotes en obras de carretera forma parte de una serie de un documento de divulgación tecnológica elaborados. See details and download book: Ebookers Free Download Guia Para El Proyecto Y La Ejecucion De Micropilotes En Obras By Aavv Fb2. Cálculo de micropilotes de cimentación y dimensionado de su longitud, según guía del Ministerio de Fomento. ESFUERZOS Y REACCIONES. Cálculo de Viga .
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The mechanical property studied was compressive strength, since as noted above, this is the main parameter used in codes and standards for determining whether a cement is apt for such applications. Portland cement grouts made with the same w: This improvement is related to the hydraulic properties of blast furnace slag.
Post-submersion absorption furnishes information on the pore volume in a material. Chloride resistance in grout is an area of particular interest, since these ions are among the most aggressive corrosion inducers in reinforcement embedded microplotes micropiles and soil anchors, particularly guja marine environments or structures in contact with high chloride- or sulfate-content water.
In Spain, the grout for these special technical applications is generally mkcropilotes with portland cement, although the codes and standards in place stipulate only the minimum compressive strength required, with no mention of cement type.
The measure of electrical resistivity of cement paste or concrete is an indirect method for determining its steady state chloride diffusion coefficient D s 20 This study, as noted earlier, aimed to analyse the behaviour of cement grout, not concrete. Other cylindrical specimens were cast to diameters of 10 and 15 cm and a height of 30 cm.
Nonetheless, if design specifications call for compressive strength greater than such minimum values, and blast furnace slag cement grout in which strength gain is slower is to be used, the micropiles or soil anchors concerned should be loaded at a later age, depending on the w: In Spain cement grout for micropiles is usually prepared with type I portland cement, although no cement type is explicitly specified in the Ministry of Internal Development’s guide for designing and building micropiles in road works 2whose provisions in this regard are confined to minimum compressive strength and cement strength gguia.
All the grouts studied here also met these specifications, with the exception of the CEM I materials with a w: In this study, the variation in the diffusion coefficient D s was monitored through the age of 90 days. Those texts also establish a range of acceptable water: The appearance of these cracks, in micripilotes with a scantly refined early age pore network, might explain the high effective porosity values observed for the CEM III material.
Specimen electrical resistivity was measured directly on a Proceq analyser.
A number of environmental benefits derive from the use of active cement additions to manufacture concrete. In the day specimens, the highest resistivity values were recorded for the CEM III grouts, a finding that concurred with earlier reports Here it was determined in cement paste specimens using the Wenner four-point test 20 described in Spanish standard UNE The penetration of water under pressure is a test 29 recommended in Spanish Structural Concrete Code EHE 30 to measure water permeability in concrete.
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Climent Universidad de Alicante, Spain. In light of the foregoing, in this study compressive strength was determined on the 7- and day specimens prepared as described above.
The code also establishes a series of maximum depth values, depending on the type of environment to which the concrete is exposed. It also provides that in grout used as anti-corrosion protection for the reinforcement the w: Article Tools Print this article.
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Durability and compressive strength of blast furnace slag-based cement grout for special geotechnical applications. Three prismatic and two cylindrical specimens were tested per cement type and w: Pre-trial specimen conditioning may have also affected these short-term effective porosity findings.
Electrochemical techniques for measuring metallic corrosion – Test methods for on site measurement of resistivity of concrete. The main conclusions that can be drawn from the present findings are listed below.
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This research aimed to characterise durability-related properties and compressive strength in cement grout prepared with a commercial cement blended with blast furnace slag at different w: Guua products formed during slag hydration induce microstructural refinement in the mortar and concrete 67 Nonetheless, this indirect method for calculating the diffusion coefficient obviates the beneficial effect of the higher aluminate content in CEM III grout 15 on chloride resistance.
Because the grout in these applications hardens in contact with the surrounding terrain, exposing it to possible aggressive agents, its properties were characterised from very early ages 2 days and up to 90 days.
Slag-blended cement grout exhibits more favourable long-term durability properties than portland cement grout. This parameter is an indirect measure of connectivity and pore size in a material. Several studies have shown that mortars and concretes prepared with cements microiplotes blast furnace slag perform well in many applications 6 — 8particularly for structures in marine environments 9 — One of the foremost such additions is ugia furnace slag, whose effects on the properties of cement-based materials are the object of considerable research 6.
Although the former procedure entails a lower risk of microstructural alterations due to the lower drying temperature, its implementation calls for fairly long test times on the order of at least one month for each condition tested. Figure 1 a contains elevation and cross-section sketches of a micropile with steel tube reinforcement. These aluminates, formed as a result of the hydration of the high Al 2 O 3 content in blast furnace slag, react with chlorides to form chloraluminates, thereby preventing ion diffusion across the material Nonetheless, the effect on the in-service properties durability and mechanical strength of the slag cement grout used in special geotechnical applications such as micropiles and soil anchors has not been researched.
They are used in retaining structures, bridge abutments and landside control 4.