Adobe Blocks Research Articles

Strength and elasto-plastic properties of non-industrial building materials manufactured with clay as a natural binder

The objective of this article is to study the mechanical performances of non-industrial materials made with soils containing argillaceous minerals as the sole binder (materials referred to as earthen). The renewed interest in earthen construction requires, in the current context, a scientific approach to these materials and a re-examination of certain techniques such as that of adobes. These adobes are obtained starting with very argillaceous soil saturated with water and poured into wooden moulds. Thus with a soil containing 25% clay, two types of adobe were studied: traditional adobe and Pressed Adobe Blocks (PABs). They were made with a variation in moulding water. Once dried, they were subjected to an unconfined compression test with three loaded and unloaded cycles at 30% of the compressive strength. This test, which takes into account the specificity of adobes, made it possible to determine their compressive strength, initial tangent modulus ( E t) and equivalent modulus during cycles ( E eq). From the results obtained, it appears that the mechanical performances of adobes depend on the moulding water content ( W m) and the manufacturing process used. The PABs with a lower W m have a higher compressive strength than the adobes. Moreover, they are more homogeneous, although both types of adobe have an elastoplastic behavior. Therefore, for laboratory testing the use of PABs is recommended rather than the use of adobe.

Optimum ventilation based on the overall ventilation effectiveness for temperature distribution in ventilated cavities

A numerical study of conjugated heat transfer in a ventilated cavity was carried out in order to analyze temperature distribution effectiveness inside it, and to determine a good ventilation configuration. The space was represented by a ventilated cavity under turbulent flow regime. All the walls were considered adiabatic, except the vertical wall on right, which was defined as a conductive opaque wall with a gap in its lower side for the incoming air. The conductive wall is submitted to a constant heat flux of 736 W/m 2 and it is considered to interact with the outside ambient. Four cases for the air exhaust location were considered for the analysis; the incoming air velocity was varying depending on the Reynolds number between 2 × 10 3 ⩽ Re ⩽ 4 × 10 4 . The conductive wall was analyzed for two different materials (construction brick and adobe block) and three different widths each (0.1, 0.2 and 0.3 m). The mass, momentum and energy equations, coupled with the turbulence model k – ε were discretized in finite volumes. From the results can be concluded that the 0.3 m width adobe block is the appropriate to minimize thermal load gains to the inside of the room and it helps to reduce the efforts made on ventilation to remove heat. Regarding the air exhaust location, it was concluded that the right side of the upper horizontal wall was the best position for the air exhaust for a Reynolds number between 5 × 10 3 and 1 × 10 4 based on the effectiveness of temperature distribution and velocity according to ASHRAE Standard 55, Thermal environment conditions for human occupancy, 2004 [1].

Durability of reinforced adobe exposed to chloride ions

One of the primary shortcomings of adobe, a dried mudblock stabilized with sisal hemp and cement widely used across all of Latin America, is its dimensional instability when exposed to water or aggressive environments. The present paper evaluates the electrochemical performance of reinforced adobe block after 1,000 days of exposure to a simulated marine environment. The specimens used were adobe blocks internally reinforced with 3/8-inch steel bars. The specimens were watered every two weeks: one group with potable water to simulate a natural urban environment and the other with a 3% sodium chloride solution to simulate a marine environment.Chloride penetration in powder extracted from the specimens was determined using the Mohr method. Electrochemical measurements included Gecor 6 electric potential(Eo) and corrosion intensity (icorr) readings. The final conclusion drawn from an analysis of the results was that in all cases the amount of free chlorides present sufficed to depassivate reinforcing steel and that the system component providing the most effective protection was the rough casting mortar. Consequently, this type of adobe mixes is not recommended for use in marine or industrial environments.

THE REALITY AND EXPECTATION OF THERMAL INSULATION OF HOUSING BUILDINGS: THE CASE OF RIYADH CITY IN THE KINGDOM OF SAUDI ARABIA

Being the largest in land occupation and population, City of Riyadh has the largest number of buildings in the Arab Gulf Countries. The assumption among practitioners that building external walls with insulated cement or adobe block will provide thermal insulation is wide spread. Any thermal insulation to any building should include all external horizontal and vertical structural elements beside windows and doors regardless of the used material or method of construction. The aim of the study is to represent the reality of thermal insulation to the city's housing buildings thorough the clarification of the practitioners' and clients' and related agencies' understanding of building thermal insulation. All necessary data were collected by using sample of housing units selected randomly as well as open-ended interviews to randomly selected practitioners, clients and engineers in the licensing department at the Municipality of Riyadh and the Saudi Electricity Company. Before mandatory application of housing building thermal insulation, it is necessary to implement the following regulations: 1- No issuing of building permit to new housing buildings which its construction drawings do not have a full thermal insulation. 2- The introduction of mandatory site supervision by the designer to insure the full and accurate implementation of thermal insulation. 3- Water and electricity services should be denied to any housing units does not have a written report signed by the Municipality of Riyadh and the consultant office indicating the full implementation of thermal insulation. The Municipality of Riyadh with its current authority can not insure the full implementation of thermal insulation in housing units without the starting the use of Building Occupancy Permits as a toll to insure the inclusion of full thermal insulation in new and old buildings.

Increasing the Strength of Soil for Adobe Construction

Adobe structures offer a number of advantages such as providing a high level of physical comfort conditions, low initial costs and low lifecycle costs. These characteristics of adobe structures make them an alternative technology for pursuing sustainable construction. Despite their advantages, adobe structures have some shortcomings. Adobe is brittle and it has a low compressive and tensile strength. Up to now, great losses have occurred due to earthquakes. A huge number of people living in adobe structures have lost their lives and there has been great damage to these buildings. Besides this, low water resistance is its weakest feature. This research addresses shortcomings of adobe structures. It explores alternative ways of increasing compressive strength, toughness, flexibility and water resistance of the adobe blocks, It concludes with proposing an alternative house design.

Comprobaciones resistentes de elementos constructivos de tierra

This work has the purpose to compare, by means of different tests on adobe bricks and masonry, the obtained resistant properties and those of other similar works carried out in countries having a wide tradition and knowledge about earth as construction material. Elements (adobe bricks and blocks) have been tested to compression and bending, and masonry made of those elements to compression and diagonal compression.