Eddie Naldoza, CPEng ASEAN APEC Engineer

12/02/2023

Breathtaking views in Danglas, Abra

28/01/2021

Question:
What are the adverse effects of Asphalt on Steel Reinforcements in Concrete Deck Slab, if the Asphalt Pavement happens to have come in direct contact with the Rebar? (aside from Thermal effects)

My take on this is that, not the Asphalt that has direct effect on the Reinforced Concrete Deck Slab but heat and temperature does. Since Steel has a greater Coefficient of Expansion than Concrete, and while the Steel Reinforcements are exposed to or in contract with Asphalt, during Thermal Action the Steel will expand more rapidly and much earlier than the concrete, being a heterogenous composite material. In Longterm, and during Cyclic and Seasonal Variations (summer time-cold season) as the Steel expands and contracts routinely, and not in the same rate as the concrete would, the concrete surrounding the Steel will develop microcracks, until such time that these cracks will develop further which could affect and weaken the bond between Steel and Concrete. Weak bond between the two materials will affect both the strength and durability of the composite material, as we know. When cracks around the Steel reinforcements start to propagate, big chances of corrosion will follow suit. This is just my own analysis of the possible scenario.

12/12/2020

16/09/2020

My Comment and Opinion on RA 9266:

05/07/2020

Question: Do ACPEs (or the ACPER) may be Recognized internationally as "CHARTERED ENGINEERS" similar, equivalent or comparable to UK's & Ireland's CEng, Australia's & New Zealand's CPEng and Europe's (FEANI) Eur.Ing. Titles?

Answer: YES!

Please find below International Aggrement for such Recognition under the WTO-GATS.

This post does not particularly suggests that ASEAN CPEng should have to be admitted to MIPENZ/MIEAust CPEng or the UK&Irelands CEng, through (direct) Mutual Agreements. The intent of this post is to let the World know that there are also qualified Chartered Engineers in the ASEAN Region, and not just in NZ/Australian Region or European Region. We intend to tell the International Trades and Economies that they can also hire equally qualified ASEAN Engineers and to not just limit their preferences to American or Australian or European Engineers. In other words, we ASEAN Engineers should not have to join and become Chartered Engineers with such Engineering Institutions in other countries in order to be recognized internationally as Chartered Engineers, because we are, by our own rights and privileges, Chartered Engineers.

25/06/2020

Lesson Learnt:

'Sometimes, a very minor editing of text in AutoCAD could cost you Millions of Money'

To the Designers/Engineering Consultants:
Please avoid making changes to the Tender Documents after the Contract has been Awarded to a Contractor and when such Documents have been Approved or Issued For Construction (A/IFC). Also, avoid making Revisions to the A/IFC Documents at the start of Construction. Any change constitute Variations in the Contract and a clever Contractor would not hesitate to grab every opportunity to claim for such variation, even at the very onset or earliest beginning of the project.

"Kasi baka wala ka nang kitain, tapos abonado ka pa pag nag-Claim ang Contractor ng Variation Order."

04/04/2020

In this difficult time, we experience (or might soon face severe) lack of Medical People, such as Doctors and Nurses; -our Frontliners and Heroes against this dreadful and deadly Pandemic. It is not a question now of who are more qualified to practice Medicine or Nursing professions. Instead, it is the question of who has the courage and bravery to face the battle against the Pandemic.

Just a wild thought, suggestion and question amidst this calamity, if at all possible;
Could the Professional Regulation Commission grant 'Special Licenses' to Medicine and Nursing Graduates that took the Board Exams and were unsuccessful, but have the courage, bravery, knowledge, ample experience and training and are ready and willing to face the challenges? Noting that these people have earned the same Degrees in the medical field and science. To note further that only about 30% of the graduates pass the Board Exams and that there is a plenty more who might be more qualified....

If so, then this could be a way to augment our Medical Fighting Forces . . .

What do you think?

28/02/2020

For years, I have been thinking about what Benefit (Environmental and Sustainability) and Cost-effectiveness, the (local/household) "Rainwater Harvesting" could bring about and yet I still fail to ascertain them. Perhaps somebody could help out, so I could be enlightened...

This is the situation:
In a normal/standard Philippine household setting, the maximum Rainwater that could be harvested at a particular rainfall event is only around 2 - 3 cu.m. (or 5 to 7 drums). This could translate to about 6% savings in the standard monthly household water consumption. The harvested Rainwater when used for cleaning, washing or flushing toilets could only last for about a week. In modern houses or buildings, obviously, drums are not viable and a dedicated water tank (collector and treatment tank) and pump(s) are necessary in order to maximize the use and efficiently utilize the harvested Rainwater. This idea clearly and undoubtedly requires a lot of money and space within the Building. Designing the Rainwater harvester or collector system alone has a significant impact on the structure, aesthetics and economy (budget) of the building. The cost could be around P50,000 to P100,000 at a minimum which could even reach up to P200,000 to P500,000 depending on the size and sophistication of the design and its location in the building. This cost does not include the expenses for operation (electricity) and maintenance.

On the otherhand, the cost of adequate and continuous supply of Potable Water, on a monthly basis per household, is only around P500 (or even lesser). Therefore, the 6% savings from the harvested Rainwater could be around P30 per month.

Basically, the Return of your P50,000 minimal investment for Rainwater Harvesting could be 1,667 months or 139 years, or even longer if you invested more.

What if it did not rain much in a particular season?

What will be the significant impact, of Rainwater Harvesting, on the Environment and Sustainability compared to the above?

What if the P50,000 per household is instead contributed to build a Community Water Treatment Plant?

06/11/2019

Scenario:
Consultants conditionally (not fully) accepted an alternative material and rejected the methodology. Contractor proceeded anyway at own risk. Delays incurred due to lack of approval, rejection and failure to comply with the requirement. In order to save time, Consultants (as directed by the Client) helped the Contractor to achieve acceptability of the material and method, to mitigate the delays. Contractor in the end, claims that since the Consultants themselves verified that the material can be accepted, the delay is not at Contractor’s fault, therefore they could claim for it against the Contract.

Lessons Learnt: ???

01/10/2019

Deviation from the requirement does not end at the approval of the proposed/new material, design, method or system to be employed/applied. The accepted deviation must be checked across and against all related specifications, implications, other requirements and functionality.

One clear example of this is a case when the required (specified) Engineered Soil Fill (Structural Fill) is replaced with other fill material such as Dune Sand. As though the Dune Sand material maybe accepted by the Client (through Deviation process, not Variation), it could have several other implications, such as when the proposed material is not covered within the Project Specification therefore a new specification, test requirements, procedures and methodologies must be set in place of the existing requirements.

18/08/2019

COMMON STRUCTURAL DESIGN FLAWS AND SHORTCOMINGS + SOME TIPS TO OVERCOME THEM (for Beginners):

Load Factors and Load Combinations:
Some, if not most, Structural Designers would simply refer and apply (directly copy) the code/standard prescribed Load Factors and Load Combinations without really analyzing its effect on the structure or the element being designed, whether adverse or beneficial. Note that the Codes present minimum requirements mainly for recommendation and guidance purposes only. As an example, in some old BS Code recommended load combinations: 1.2(DL+LL+WL), a lot of designers would just directly copy and apply the factor and combination without thinking about its applicability and the resulting effect on the structure or element. This load combination is best suited for maximizing gravity load or total downward loading effect on axial compression/reaction, shear and moment outputs. However, for the cases of maximum tension or uplift effect, the load factor and combination may be modified to 1.0DL+1.0LL-1.2WL or 0.9DL+1.0LL-1.2WL or better yet, 0.9DL-1.0WL, and so on, depending on the Designers intention or desired beneficial outcome.

In one Structural Design Calculation for Scaffolding and Working Platform I reviewed, I found that the Designer have used a load combination:
1.4DL+2.0LL+2.0WL
The Designer might be thinking that he is designing the Scaffolding assembly conservatively and very strong, that it could withstand higher or double intensity loads. But in fact he failed to think that when the Wind is very strong, no worker is permitted to work on the scaffolding and therefore Wind Load should not have included in the combination. Instead, the load combination 0.9DL+/-2.0WL should have been added to come up with a resulting maximum lateral stability and resistance to uplift (flying away) of the scaffolding against maximum/high wind velocity, while minimizing resistance contributed by weights or gravity loads.

Similar observation is commonly encountered in the Design of Holding Down Bolts (Anchor Bollts) and Base Plates of non-building frame columns, i.e. Mast, Post, Billboard, etc. As the term suggests, the purpose and intention is to hold down the Column Base against Pull-out or Tension Force due to Wind Loading (basically). Holding Down Bolts do not resist Compression Force. Forces due to Wind must always act in the opposite direction with Dead Load (or DL+LL), hence 0.9DL-1.2WL combination would be most appropriate.

Loading Pattern or Alternate Span Loading:

(to be continued . . .)