Watkins Concrete Block’s Post

Architecturally Speaking: October Topic: NOT ALL CONCRETE IS THE SAME - Low Embodied Carbon Dry-Cast Concrete Masonry Description/Uses/Benefits: Concrete Masonry Units (CMU) are made with dry-cast concrete (zero-slump) which use less water and cement than poured-in-place concrete (typically referred to as wet-cast concrete). The unique structure of dry-cast concrete enables increased rates of carbon dioxide sequestration (aka carbon uptake, carbonation, limestone mineralization), and at a much faster rate when compared with wet-cast concrete. In addition to CMU assemblies using less cement and sequestering more carbon dioxide, they also use less volume of concrete due to their cores or voids. We can capture all 3 of these factors which drastically lower embodied carbon by looking at embodied carbon cradle-to-gate Life Cycle Analysis (LCA) studies. In recent industry research incorporating CMU specific sequestration testing, several wall assemblies were compared including a CMU cavity wall with architectural CMU veneer, insulated concrete forms (ICF) with clay brick veneer, tilt-up with thin brick veneer, wood frame with metal panel, and steel frame with metal panel. A1-A3 (cradle to gate) was considered, which is generally where concrete structures are the most embodied carbon intensive. Durability, resilience and low maintenance in the use phase of the building (which is where concrete shines) was not part of the study. Drumroll please… At the gate, CMU structures are closer in embodied carbon to the framed assemblies than they are to the other concrete assemblies! 2 years into the use phase, the concrete block cavity wall has similar embodied carbon compared to the framed assemblies. 20 years into the use phase, it is projected that the concrete block cavity wall will have lower embodied carbon when compared to the framed assemblies. And that’s the Beauty of Block.

Architecturally Speaking: October Topic: NOT ALL CONCRETE IS THE SAME - Low Embodied Carbon Dry-Cast Concrete Masonry Description/Uses/Benefits: Concrete Masonry Units (CMU) are made with dry-cast concrete (zero-slump) which use less water and cement than poured-in-place concrete (typically referred to as wet-cast concrete). The unique structure of dry-cast concrete enables increased rates of carbon dioxide sequestration (aka carbon uptake, carbonation, limestone mineralization), and at a much faster rate when compared with wet-cast concrete. In addition to CMU assemblies using less cement and sequestering more carbon dioxide, they also use less volume of concrete due to their cores or voids. We can capture all 3 of these factors which drastically lower embodied carbon by looking at embodied carbon cradle-to-gate Life Cycle Analysis (LCA) studies. In recent industry research incorporating CMU specific sequestration testing, several wall assemblies were compared including a CMU cavity wall with architectural CMU veneer, insulated concrete forms (ICF) with clay brick veneer, tilt-up with thin brick veneer, wood frame with metal panel, and steel frame with metal panel. A1-A3 (cradle to gate) was considered, which is generally where concrete structures are the most embodied carbon intensive. Durability, resilience and low maintenance in the use phase of the building (which is where concrete shines) was not part of the study. Drumroll please… At the gate, CMU structures are closer in embodied carbon to the framed assemblies than they are to the other concrete assemblies! 2 years into the use phase, the concrete block cavity wall has similar embodied carbon compared to the framed assemblies. 20 years into the use phase, it is projected that the concrete block cavity wall will have lower embodied carbon when compared to the framed assemblies. And that’s the Beauty of Block.

Architecturally Speaking: October Topic: NOT ALL CONCRETE IS THE SAME - Low Embodied Carbon Dry-Cast Concrete Masonry Description/Uses/Benefits: Concrete Masonry Units (CMU) are made with dry-cast concrete (zero-slump) which use less water and cement than poured-in-place concrete (typically referred to as wet-cast concrete). The unique structure of dry-cast concrete enables increased rates of carbon dioxide sequestration (aka carbon uptake, carbonation, limestone mineralization), and at a much faster rate when compared with wet-cast concrete. In addition to CMU assemblies using less cement and sequestering more carbon dioxide, they also use less volume of concrete due to their cores or voids. We can capture all 3 of these factors which drastically lower embodied carbon by looking at embodied carbon cradle-to-gate Life Cycle Analysis (LCA) studies. In recent industry research incorporating CMU specific sequestration testing, several wall assemblies were compared including a CMU cavity wall with architectural CMU veneer, insulated concrete forms (ICF) with clay brick veneer, tilt-up with thin brick veneer, wood frame with metal panel, and steel frame with metal panel. A1-A3 (cradle to gate) was considered, which is generally where concrete structures are the most embodied carbon intensive. Durability, resilience and low maintenance in the use phase of the building (which is where concrete shines) was not part of the study. Drumroll please… At the gate, CMU structures are closer in embodied carbon to the framed assemblies than they are to the other concrete assemblies! 2 years into the use phase, the concrete block cavity wall has similar embodied carbon compared to the framed assemblies. 20 years into the use phase, it is projected that the concrete block cavity wall will have lower embodied carbon when compared to the framed assemblies. And that’s the Beauty of Block.

Heading: Exploring Various Types of Shallow Foundations: A Visual Guide Explanation: 1. Pad Foundation: A simple, square or rectangular concrete base that spreads the load of a single column. Used for smaller structures where loads are light and the ground conditions are favorable. 2. Stepped Footing: A variation of pad foundation where the footing steps down in layers to adjust for different soil depths or to support sloping ground. This design increases the stability of the structure. 3. Sloped Footing: Similar to stepped footing but with a continuous slope instead of distinct steps. It is also used to counter uneven ground conditions, offering better load distribution. 4. Eccentric Footing: Used when a column is placed near a boundary and can't be centrally supported. The footing is designed to account for the eccentric loading by balancing the weight distribution, often using a trapezoidal or rectangular shape. 5. Combined Footing: A single footing that supports two or more columns, typically used when columns are placed too close for individual footings, or when there's uneven load distribution between columns. 6. Strip Footing: A continuous foundation that supports a line of columns or a load-bearing wall. It is long and narrow, distributing the load evenly along the entire length of the wall or row of columns. 7. Strap Footing: Two footings connected by a strap beam that helps distribute the load evenly between a heavily loaded and lightly loaded column. This is useful when constraints like property lines limit footing design. 8. Raft/Mat Foundation: A large, solid slab that supports the entire structure. It is typically used for buildings with weak soil conditions, as it spreads the load across the entire area of the foundation, minimizing settlement. Each type of foundation in the diagram has its unique design based on the load distribution, soil conditions, and structural requirements. Proper selection ensures stability and longevity of the building.

Benefits of Bubble Deck Slab: 1. Reduced Weight 2. Material Efficiency 3. Faster Construction 4. Improved Thermal Insulation This leads to lighter foundation and reduced column sizes along with larger column to column spacings. #structuredesign #structuredesigner #structureengineer #structureengineering #constructionwork #civil #civilengineering #architecture #architect #technology #construction #buildings #architecture #architect #etabs #staad

Why there is always a difference between the calculated spacing and actual spacing between two bars in the RC beams? In reinforced concrete (RC) design, the spacing between reinforcement bars is a critical factor for ensuring proper structural performance. However, there is often a noticeable difference between the spacing calculated during the design phase and the actual spacing achieved during construction. In the design stage we usually calculate the spacing as in this example where we have a section with a width of 300 mm that contains 3 bars, each with a diameter of 16 mm. The stirrups used have a diameter of 10 mm with a concrete cover of 40 mm. The common approach is to calculate the clear spacing between the bars as follows: 1- Effective width for bar placement: We subtract the cover and the stirrup diameter from both sides of the section to find the effective width for bar placement: Effective width=300 mm−2×(40 mm+10 mm)=300 mm−100 mm=200 mm 2- Total bar width: The total width taken up by the three 16 mm diameter bars is: Total bar width=3×16 mm=48 mm 3- Clear spacing between bars: The remaining width between the bars is: Remaining width=Effective width−Total bar width=200 mm−48 mm=152  Clear spacing between two bars as we have two spaces=152 mm/2=76 mm as in the figure. This approach seems correct, and in many cases, it would be used for calculating bar spacing. However, in practice, the actual spacing between the bars often ends up being less than 76 mm. The main reason for this discrepancy is that, while we account for the stirrup bend diameter in our calculations, we often fail to consider the minimum inside diameter of the stirrups. For instance, the stirrup bends at corners may cause the internal space to reduce, leaving less room for the main bars. When the stirrups are installed, this additional reduction in effective space isn't considered, leading to tighter bar spacing which is approximately 13 mm tighter in our example. Does it really matter? Yes, accounting for the minimum inside diameter of stirrups ensures that the actual spacing between the bars during construction aligns more closely with the calculated spacing. Overlooking this factor can lead to congestion, reduced spacing, and potential challenges in concrete placement, which may compromise structural performance.

Unlike traditional reinforced concrete slabs, which rely solely on the strength of the concrete and embedded steel reinforcement bars, post-tensioned slabs incorporate high-strength steel tendons that are tensioned after the concrete has cured. Post tensioning enables engineers to optimize floor structural performance, increase spans, reduce material usage, and enhance durability. This article offers insights into the process of designing a PT slab and the implications of post-tensioning on the overall structure. #structuralengineer #civilengineer #postensionedfloor #civilconstruction #floordesign #floorslabs #Eurocode2 #prestressedconcrete A Guide to the Design of Post-tensioned Slabs

Good Idea. Poor in durability and performance especially in hourdi roof tops

A Posttensioned flat slab is the simplest type of posttensioned slab. It is essentially a flat slab that has been enhanced using high-strength steel tendons to apply compression after the concrete has set thereby reducing deflection of the concrete floor. Find in this article a worked example on the design of post-tensioned flat slab. #structuralengineer #civilengineer #prestressed #prestressedfloor #postensioning #civilconstruction Designing a Post-tensioned Flat Slab | Worked Example https://lnkd.in/d69GPfv7

BubbleDeck technology, construction using hollow plastic balls embedded in a slab of concrete, is growing in adoption around the world, including parts of Europe, North America, and Australia. Why use BubbleDeck for bridges, overpasses, and other structures? 1. **Reduced Weight**: The incorporation of hollow plastic spheres reduces the overall weight of the concrete slabs by 30-50%. This lighter weight translates to less load on the foundation and supporting structures, beneficial for overpasses and bridges. 2. **Material Efficiency**: By replacing concrete with hollow spheres, BubbleDeck uses approximately 30-50% less concrete than traditional solid slabs. 3. **Increased Span Lengths**: The reduced weight allows for longer spans without the need for intermediate supports. In bridge construction where longer spans less weight can reduce the number of piers or supports needed. 4. **Flexibility in Design**: BubbleDeck slabs can be easily shaped and customized, offering architectural and structural design flexibility. 5. **Faster Construction**: As the slabs can be prefabricated off-site and easily installed, construction time can be significantly reduced. 6. **Improved Durability**: The system can lead to improved durability of the structure. The reduction in concrete volume lowers the risk of cracking and increases the lifespan of the material. 7. **Enhanced Thermal and Acoustic Insulation**: The air gaps provided by the hollow spheres provide better insulation properties compared to traditional solid concrete slabs, which can be beneficial for indoor environments in buildings. Using 30% less concrete in all new construction over the next ten years would have significant environmental benefits. Concrete production is highly resource-intensive and environmentally impactful. 1. **Reduction in Carbon Emissions**: Cement manufacturing is one of the largest sources of industrial CO2 emissions globally, accounting for about 8% of global CO2 emissions. 2. **Conservation of Resources**: Manufacturing concrete consumes vast amounts of resources, including water, sand, and gravel. Sand shortages in certain areas are real. 3. **Energy Savings**: The production of cement, the most energy-intensive component of concrete, involves high-temperature processes that consume a lot of energy, primarily from fossil fuels. 4. **Decreased Waste**: Concrete production and demolition contribute to large amounts of construction and demolition waste. 5. **Mitigation of Environmental Impact**: The extraction of raw materials for concrete production has significant environmental impacts, including habitat destruction, water depletion, and pollution. 6. **Improvements in Air Quality**: The reduction in dust and other pollutants from both cement production and construction activities would improve air quality. What will be the effect on demolition safety, disposal or recycling? This design thinking and innovation is a great example for any field.