# Method 3: Detailed Event Sequence + Rigorous Creep and Shrinkage Allowance

In this approach, a detailed event sequence has been defined which includes propping loads at early events to create an overall load history. Creep is considered rigorously alongside this load history by setting the Aging coefficient to Automatic. This means that an effective composite modulus value to the end of each event is calculated in accordance with the Concrete Society Technical Report 58.

# Download and open the tutorial model

# Establish some slab reinforcement

Prior to running a Slab Deflection Analysis, a reasonable level of slab reinforcement should already be provided. This can be achieved by designing all slabs and patches as follows:

- From the Analyze toolbar, click Analyze All (Static)
- From the Design toolbar, click Design Slabs
- From the Design toolbar, click Design Patches

# Review the Detailed Event Sequence

**To display the Event
Sequence**

# Set up Rigorous Creep

This method requires that the **Aging coefficient** is set to Automatic. Creep
is then considered automatically as part of the analysis for each event
sequence.

A user defined allowance for Shrinkage effects in the total deflection is also specified.

**To specify the multiplier
for shrinkage effects only but also consider creep in the analysis**

# Review the Restraint Constant

# Perform Iterative Slab Deflection Analysis

# Adjust the Restraint Constant and Re-analyze

Initially the Restraint Constant was set assuming significant restraint; we will now investigate the effect of assuming insignificant restraint.

# Generate Composite Modulus Report

An effective composite modulus
report can be obtained by right clicking a slab and choosing **Export Eff.
modulus report to Excel**. The report details the composite modulus
E_{c} determined for each event.

**To display the Composite
Modulus Report:**

# Summary of Results

Using the Detailed event sequence plus rigorous creep and shrinkage allowance method, the results can be tabulated below:

Approach | Restraint Constant for Modulus of Rupture | Creep approach |
Assumed Shrinkage % |
Total deflection (Final load event) |
---|---|---|---|---|

ACI 435 (creep included in analysis) | 4.0 | C_{u} = 2.35, h = 2 and χ = automatic based on TR58 |
25% | 1.5” |

ACI 435 (creep included in analysis) | 7.5 | C_{u} = 2.35, h = 2 and χ = automatic based on TR58 |
25% | 1.0” |

# Next steps

- Having obtained results for all three methods, observations on the different methods are discussed.
- Finally, using results from one of the methods, deflection checks are performed using check lines and an output report is generated.