Concrete grades and steel reinforcement are key components in the design of high-rise building structures, and structural engineers play a crucial role in their design. 

Here's an overview of how concrete grades and steel reinforcement are designed for high-rise building construction:
Concrete Grades:

Structural Requirements:
The structural engineer assesses the specific requirements of the building, including its load-bearing capacity, intended use, and design life. This helps determine the minimum concrete grade needed for the structure.

Structural Design Codes: 
The engineer refers to relevant design codes, such as IS 456 in India or ACI 318 in the United States, which provide guidelines for selecting concrete grades based on various factors, including the magnitude of loads, exposure conditions, and environmental factors.

Strength Considerations: 
The structural engineer determines the required compressive strength of concrete based on the design loads and safety factors. The concrete grade is then selected based on the desired strength, such as M20, M30, or higher grades.

Mix Design: 
The engineer collaborates with a concrete technologist or performs a concrete mix design to determine the appropriate proportions of cement, aggregates, water, and admixtures. This ensures that the concrete mix achieves the required strength and durability while considering factors like workability and construction constraints.

Quality Control: 
The structural engineer sets specifications for quality control measures during concrete production, such as testing procedures, frequency of tests, and acceptance criteria. This helps ensure that the concrete used in the construction meets the specified grade and strength requirements.

Steel Reinforcement:

Structural Design Loads: 
The structural engineer determines the design loads on the building, such as dead loads, live loads, wind loads, and seismic loads. These loads are considered in the design of the steel reinforcement to ensure the structure can safely withstand the forces.

Structural Design Codes: 
The engineer refers to design codes, such as IS 456 or ACI 318, which provide guidelines for selecting appropriate steel reinforcement based on the structural requirements. These codes specify the minimum reinforcement ratios and the allowable stresses for different structural elements.

Reinforcement Layout:
The engineer determines the required reinforcement layout for each structural element, such as columns, beams, slabs, and walls. This involves calculating the area of reinforcement based on the loads and using engineering judgment to distribute the reinforcement effectively.

Bar Selection and Sizing: 
The engineer selects the appropriate reinforcement bars based on their yield strength, ductility, and corrosion resistance. Bar sizes and spacing are determined to meet the design requirements, accounting for factors like cover thickness, concrete confinement, and construction feasibility.

Detailing and Anchorage: 
The engineer provides detailed drawings and specifications for the placement, lap lengths, and anchorage of reinforcement. This ensures proper transfer of forces between the reinforcement and the surrounding concrete, avoiding premature failure and ensuring structural integrity.

Quality Assurance: 
The structural engineer sets specifications for quality assurance during reinforcement installation, such as visual inspection, testing, and documentation. This helps verify that the reinforcement is correctly placed and meets the design requirements.

Throughout the design process, structural engineers use structural analysis software and calculations to assess the behavior of the building under different loading conditions and ensure that the selected concrete grades and steel reinforcement can withstand the expected forces and deformations. 

They also consider other factors like fire resistance, durability, and construction constraints to arrive at an optimized design.

It is important to note that the specific design considerations and practices may vary depending on local building codes, project specifications, and engineering practices. Consulting with experienced structural engineers and following the relevant design codes and standards is essential for the safe and efficient design of high-rise building structures.