Final answer:
A poured concrete wall is typically considered stronger than a concrete block wall due to fewer joints and potential for steel reinforcement. The poured wall also offers better insulation and energy efficiency because of its monolithic nature. Calculations for thermal stress are based on the modulus of elasticity and temperature changes.
Step-by-step explanation:
Strength Comparison Between Poured Concrete Walls and Concrete Block Walls
When comparing the strength of a poured concrete wall to a concrete block wall of the same dimensions, several factors come into play. Generally, a poured concrete wall is considered to have greater strength and structural integrity than a concrete block wall with equivalent dimensions. This is largely because poured concrete walls have fewer joints, and therefore less potential points of weakness, as opposed to concrete block walls which are assembled using individual blocks held together by mortar.
The ultimate compressive strength of concrete is significantly high, ensuring that both types of walls are resistant to breaking under compression. However, poured concrete can be reinforced with steel, which can further enhance its strength in tension and flexure. While the ultimate shear strength of concrete is lower than its compressive strength, this is more of an issue for concrete block walls since they are more likely to experience failures at mortar joints, either by cracking or chipping, under heavy shear loads.
Lastly, considering the thermal properties, a monolithic poured concrete wall can provide better insulation due to its mass and continuity, reducing the potential need for additional heating or cooling infrastructure. This is based on the principle that thicker, denser walls have greater thermal mass, leading to improved energy efficiency.
Calculating Thermal Stress: To calculate the thermal stress that concrete might undergo due to temperature changes, we use the formula σ = Α × E × ΔT, where σ is stress, Α is the coefficient of thermal expansion, E is the modulus of elasticity, and ΔT is the change in temperature. Given the compressive Young's modulus (Y) for concrete, we can find the stress induced by the temperature change from 5 °C to 38 °C.